feat(opencode): add experimental code-mode MCP adapter

Co-authored-by: Brendan Allan <git@brendonovich.dev>

.github/ISSUE_TEMPLATE/config.yml

@@ -2,4 +2,4 @@ blank_issues_enabled: false
 contact_links:
   - name: 💬 Discord Community
     url: https://discord.gg/opencode
-    about: For quick questions or real-time discussion. Note that issues are searchable and help others with the same question.
+    about: For support, troubleshooting, how-to questions, and real-time discussion.

.github/ISSUE_TEMPLATE/question.yml

@@ -1,10 +0,0 @@
-name: Question
-description: Ask a question
-body:
-  - type: textarea
-    id: question
-    attributes:
-      label: Question
-      description: What's your question?
-    validations:
-      required: true

.github/actions/setup-bun/action.yml

@@ -8,6 +8,13 @@ inputs:
 runs:
   using: "composite"
   steps:
+    # node-gyp@latest (invoked via bunx for native install scripts) requires Node >=22;
+    # some runner images ship an older system Node on PATH
+    - name: Setup Node
+      uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
+      with:
+        node-version: "24"
+
     - name: Get baseline download URL
       id: bun-url
       shell: bash

.github/workflows/compliance-close.yml

@@ -34,10 +34,48 @@ jobs:
 
             const now = Date.now();
             const twoHours = 2 * 60 * 60 * 1000;
+            const orgMemberAssociations = new Set(['OWNER', 'MEMBER']);
+            const agentLogin = 'opencode-agent[bot]';
+            const { data: file } = await github.rest.repos.getContent({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              path: '.github/TEAM_MEMBERS',
+              ref: 'dev',
+            });
+            const teamMembers = new Set(
+              Buffer.from(file.content, 'base64')
+                .toString()
+                .split('\n')
+                .map((line) => line.trim().toLowerCase())
+                .filter(Boolean)
+            );
+
+            function isExempt(item) {
+              const login = item.user?.login?.toLowerCase();
+              return (
+                login === agentLogin ||
+                orgMemberAssociations.has(item.author_association) ||
+                (login && teamMembers.has(login))
+              );
+            }
 
             for (const item of items) {
               const isPR = !!item.pull_request;
               const kind = isPR ? 'PR' : 'issue';
+              const login = item.user?.login;
+
+              if (isExempt(item)) {
+                core.info(`Skipping ${kind} #${item.number}; author ${login || 'unknown'} is exempt`);
+                try {
+                  await github.rest.issues.removeLabel({
+                    owner: context.repo.owner,
+                    repo: context.repo.repo,
+                    issue_number: item.number,
+                    name: 'needs:compliance',
+                  });
+                } catch (e) {}
+                continue;
+              }
 
               const { data: comments } = await github.rest.issues.listComments({
                 owner: context.repo.owner,

.github/workflows/duplicate-issues.yml

@@ -17,12 +17,31 @@ jobs:
         with:
           fetch-depth: 1
 
+      - name: Check exempt issue author
+        id: author
+        run: |
+          LOGIN="${{ github.event.issue.user.login }}"
+          ASSOCIATION="${{ github.event.issue.author_association }}"
+
+          if [ "$LOGIN" = "opencode-agent[bot]" ] ||
+             [ "$ASSOCIATION" = "OWNER" ] ||
+             [ "$ASSOCIATION" = "MEMBER" ] ||
+             grep -qxiF "$LOGIN" .github/TEAM_MEMBERS; then
+            echo "skip=true" >> "$GITHUB_OUTPUT"
+            echo "Skipping issue automation for exempt author: $LOGIN ($ASSOCIATION)"
+          else
+            echo "skip=false" >> "$GITHUB_OUTPUT"
+          fi
+
       - uses: ./.github/actions/setup-bun
+        if: steps.author.outputs.skip != 'true'
 
       - name: Install opencode
+        if: steps.author.outputs.skip != 'true'
         run: curl -fsSL https://opencode.ai/install | bash
 
       - name: Check duplicates and compliance
+        if: steps.author.outputs.skip != 'true'
         env:
           OPENCODE_API_KEY: ${{ secrets.OPENCODE_API_KEY }}
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
@@ -38,6 +57,7 @@ jobs:
           opencode run -m opencode/claude-sonnet-4-6 "A new issue has been created:
 
           Issue number: ${{ github.event.issue.number }}
+          Issue author association: ${{ github.event.issue.author_association }}
 
           Lookup this issue with gh issue view ${{ github.event.issue.number }}.
 
@@ -49,6 +69,8 @@ jobs:
 
           Check whether the issue follows our contributing guidelines and issue templates.
 
+          If the issue author association is OWNER or MEMBER, skip this compliance check. Do not add the needs:compliance label for organization-owned issues.
+
           This project has three issue templates that every issue MUST use one of:
 
           1. Bug Report - requires a Description field with real content
@@ -83,7 +105,7 @@ jobs:
 
           Based on your findings, post a SINGLE comment on issue #${{ github.event.issue.number }}. Build the comment as follows:
 
-          If the issue is NOT compliant, start the comment with:
+          If the issue is NOT compliant and the author association is not OWNER or MEMBER, start the comment with:
           <!-- issue-compliance -->
           Then explain what needs to be fixed and that they have 2 hours to edit the issue before it is automatically closed. Also add the label needs:compliance to the issue using: gh issue edit ${{ github.event.issue.number }} --add-label needs:compliance
 
@@ -129,12 +151,31 @@ jobs:
         with:
           fetch-depth: 1
 
+      - name: Check exempt issue author
+        id: author
+        run: |
+          LOGIN="${{ github.event.issue.user.login }}"
+          ASSOCIATION="${{ github.event.issue.author_association }}"
+
+          if [ "$LOGIN" = "opencode-agent[bot]" ] ||
+             [ "$ASSOCIATION" = "OWNER" ] ||
+             [ "$ASSOCIATION" = "MEMBER" ] ||
+             grep -qxiF "$LOGIN" .github/TEAM_MEMBERS; then
+            echo "skip=true" >> "$GITHUB_OUTPUT"
+            echo "Skipping issue automation for exempt author: $LOGIN ($ASSOCIATION)"
+          else
+            echo "skip=false" >> "$GITHUB_OUTPUT"
+          fi
+
       - uses: ./.github/actions/setup-bun
+        if: steps.author.outputs.skip != 'true'
 
       - name: Install opencode
+        if: steps.author.outputs.skip != 'true'
         run: curl -fsSL https://opencode.ai/install | bash
 
       - name: Recheck compliance
+        if: steps.author.outputs.skip != 'true'
         env:
           OPENCODE_API_KEY: ${{ secrets.OPENCODE_API_KEY }}
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
@@ -148,9 +189,12 @@ jobs:
             }
         run: |
           opencode run -m opencode/claude-sonnet-4-6 "Issue #${{ github.event.issue.number }} was previously flagged as non-compliant and has been edited.
+          Issue author association: ${{ github.event.issue.author_association }}
 
           Lookup this issue with gh issue view ${{ github.event.issue.number }}.
 
+          If the issue author association is OWNER or MEMBER, remove the needs:compliance label if present, delete the previous compliance comment if present, and do not post a new comment.
+
           Re-check whether the issue now follows our contributing guidelines and issue templates.
 
           This project has three issue templates that every issue MUST use one of:

.github/workflows/publish.yml

@@ -325,6 +325,7 @@ jobs:
         run: bun run build
         working-directory: packages/desktop
         env:
+          NODE_OPTIONS: --max-old-space-size=4096
           OPENCODE_CHANNEL: ${{ (github.ref_name == 'beta' && 'beta') || 'prod' }}
           SENTRY_AUTH_TOKEN: ${{ secrets.SENTRY_AUTH_TOKEN }}
           SENTRY_ORG: ${{ vars.SENTRY_ORG }}

.github/workflows/storybook.yml

@@ -9,6 +9,7 @@ on:
       - "bun.lock"
       - "packages/storybook/**"
       - "packages/ui/**"
+      - "packages/session-ui/**"
   pull_request:
     branches: [dev]
     paths:
@@ -17,6 +18,7 @@ on:
       - "bun.lock"
       - "packages/storybook/**"
       - "packages/ui/**"
+      - "packages/session-ui/**"
   workflow_dispatch:
 
 concurrency:

.github/workflows/test.yml

@@ -65,10 +65,15 @@ jobs:
 
       - name: Run unit tests
         timeout-minutes: 20
-        run: bun turbo test --output-logs=errors-only --log-order=grouped --log-prefix=none
+        run: GITHUB_ACTIONS=false bun turbo test
         env:
           OPENCODE_EXPERIMENTAL_DISABLE_FILEWATCHER: ${{ runner.os == 'Windows' && 'true' || 'false' }}
 
+      - name: Check generated client
+        if: runner.os == 'Linux'
+        working-directory: packages/client
+        run: bun run check:generated
+
       - name: Run HttpApi exerciser gates
         if: runner.os == 'Linux'
         working-directory: packages/opencode

.github/workflows/triage.yml

@@ -16,13 +16,32 @@ jobs:
         with:
           fetch-depth: 1
 
+      - name: Check exempt issue author
+        id: author
+        run: |
+          LOGIN="${{ github.event.issue.user.login }}"
+          ASSOCIATION="${{ github.event.issue.author_association }}"
+
+          if [ "$LOGIN" = "opencode-agent[bot]" ] ||
+             [ "$ASSOCIATION" = "OWNER" ] ||
+             [ "$ASSOCIATION" = "MEMBER" ] ||
+             grep -qxiF "$LOGIN" .github/TEAM_MEMBERS; then
+            echo "skip=true" >> "$GITHUB_OUTPUT"
+            echo "Skipping issue automation for exempt author: $LOGIN ($ASSOCIATION)"
+          else
+            echo "skip=false" >> "$GITHUB_OUTPUT"
+          fi
+
       - name: Setup Bun
+        if: steps.author.outputs.skip != 'true'
         uses: ./.github/actions/setup-bun
 
       - name: Install opencode
+        if: steps.author.outputs.skip != 'true'
         run: curl -fsSL https://opencode.ai/install | bash
 
       - name: Triage issue
+        if: steps.author.outputs.skip != 'true'
         env:
           OPENCODE_API_KEY: ${{ secrets.OPENCODE_API_KEY }}
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.prettierignore

@@ -1,2 +1,4 @@
 sst-env.d.ts
 packages/desktop/src/bindings.ts
+packages/client/src/generated/
+packages/client/src/generated-effect/

AGENTS.md

@@ -1,4 +1,6 @@
-- To regenerate the JavaScript SDK, run `./packages/sdk/js/script/build.ts`.
+- To regenerate the legacy JavaScript SDK, run `./packages/sdk/js/script/build.ts`.
+- After changing the public Protocol or Server `HttpApi`, run `bun run generate` from `packages/client`. Do not edit `src/generated` or `src/generated-effect` directly.
+- Keep runtime dependencies directed from Schema to Core and Protocol, then from Core and Protocol to Server. Client runtime code may depend on Schema and Protocol but never Core or Server; `sdk-next` composes Client, Core, and Server.
 - The default branch in this repo is `dev`.
 - Local `main` ref may not exist; use `dev` or `origin/dev` for diffs.
 
@@ -28,6 +30,7 @@ Examples: `fix(tui): simplify thinking toggle styling`, `docs: update contributi
 - Rely on type inference when possible; avoid explicit type annotations or interfaces unless necessary for exports or clarity
 - Prefer functional array methods (flatMap, filter, map) over for loops; use type guards on filter to maintain type inference downstream
 - In `src/config`, follow the existing self-export pattern at the top of the file (for example `export * as ConfigAgent from "./agent"`) when adding a new config module.
+- In Effect generators, bind services to named variables before calling methods. Do not use nested service yields such as `yield* (yield* Foo.Service).bar()`.
 
 Reduce total variable count by inlining when a value is only used once.
 
@@ -137,7 +140,7 @@ const table = sqliteTable("session", {
 
 ## Testing
 
-- Avoid mocks as much as possible
+- Avoid mocks as much as possible, you shouldn't be using globalThis.\* at all unless it's the only option.
 - Test actual implementation, do not duplicate logic into tests
 - Tests cannot run from repo root (guard: `do-not-run-tests-from-root`); run from package dirs like `packages/opencode`.
 
@@ -152,7 +155,7 @@ const table = sqliteTable("session", {
 - Keep `SessionExecution` process-global and Session-ID based. Its local implementation owns the process-local Session coordinator and discovers placement through `SessionStore` plus `LocationServiceMap.get(session.location)` only when a drain starts; no layer should take a Session ID. V2 interruption targets the active process-local ownership chain for that Session; idle or missing interruption is a no-op.
 - Keep `SessionRunner`, model resolution, tool registry, permissions, and filesystem Location-scoped. Omitted `Location.workspaceID` means implicit-local placement; explicit workspace identity remains reserved for future placement semantics.
 - Preserve one explicit `llm.stream(request)` call per provider turn and reload projected history before durable continuation. Do not bridge through legacy `SessionPrompt.loop(...)` or delegate orchestration to an in-memory tool loop.
-- Keep local Session drains process-local until clustering is implemented. `SessionRunCoordinator` joins explicit same-Session resumes, coalesces prompt wakeups, and allows different Sessions to run concurrently. Advisory wakes drain eligible durable inbox rows only; post-crash activity recovery requires a separate explicit design before it may retry provider work.
-- Keep delivery vocabulary explicit. Prompts steer by default and coalesce into the active activity at the next safe provider-turn boundary. Explicit `queue` inputs open FIFO future activities one at a time after the active activity settles.
+- Keep local Session drains process-local until clustering is implemented. `SessionRunCoordinator` joins explicit same-Session resumes, coalesces prompt wakeups, and allows different Sessions to run concurrently. Advisory wakes drain eligible durable inbox rows only; post-crash continuation recovery requires a separate explicit design before it may retry provider work. A drain has no durable identity or transcript boundary.
+- Keep delivery vocabulary explicit. Prompts steer by default and promote at the next safe provider-turn boundary while the current drain requires continuation. An explicit `queue` input remains pending until the Session would otherwise become idle; promote one queued input at that boundary, then reevaluate continuation before promoting another. Promoting any new user input resets the selected agent's provider-turn allowance; a batch of steers resets it once.
 - Keep EventV2 replay owner claims separate from clustered Session execution ownership.
 - Keep the System Context algebra, registry, and built-ins in `src/system-context`; keep Context Source producers with their observed domains, and keep Session History selection plus Context Epoch persistence Session-owned.

CONTEXT.md

@@ -39,6 +39,18 @@ An expected temporary inability to observe a **Context Source** value; the runti
 **Safe Provider-Turn Boundary**:
 The point immediately before a provider call, after durable input promotion and any required tool settlement, where context changes may be admitted chronologically.
 
+**Admitted Prompt**:
+A durable user input accepted into the Session inbox but not yet included in **Session History**.
+
+**Prompt Promotion**:
+The durable transition that removes an **Admitted Prompt** from pending input and appends its user message to **Session History**.
+
+**Provider Turn**:
+One request to a model provider and the response projected from that request.
+
+**Session Drain**:
+One process-local execution span that promotes eligible input and runs required **Provider Turns** until no immediate continuation remains. A Session Drain has no durable identity or transcript boundary.
+
 **Model Tool Output**:
 The bounded projection of a Core-executed tool result persisted in Session history and replayed to the model. A tool may shape this projection semantically, but the Tool Registry enforces the final size limit.
 
@@ -52,9 +64,27 @@ _Avoid_: Request body, wire options
 **Generation Controls**:
 Provider-neutral sampling and output controls, partitioned from provider semantics and compatibility wire fields when model metadata enters the Catalog.
 
+**Native Continuation Metadata**:
+Opaque protocol-shaped data attached to assistant content and required to continue that content natively with a compatible model, such as a reasoning signature or provider-hosted item identifier.
+
 **PTY Environment**:
 The host-supplied environment overlay applied by the server when creating a PTY, observed for the request Location and resolved PTY working directory.
 
+**OpenCode Client**:
+The generated Promise and Effect APIs derived from the public `HttpApi`; **Embedded OpenCode** shares the Effect API through an in-memory `HttpClient` against the same router and handlers.
+_Avoid_: Remote client
+
+**SDK Contract IR**:
+The runtime-neutral compiled representation of the authoritative `HttpApi`, preserving encoded and decoded type projections plus transport metadata so independent SDK emitters can choose their public value model and runtime interpreter.
+
+**Embedded OpenCode**:
+A scoped in-process host that structurally extends the **OpenCode Client**, supplies an in-memory HTTP transport, and exposes additional same-process capabilities directly.
+_Avoid_: Local implementation
+
+**Page**:
+A bounded ordered result containing `items` and opaque `previous` and `next` cursor links for navigating the same query in either direction.
+_Avoid_: Response envelope
+
 ## Relationships
 
 - A **System Context** is an opaque carrier composed from zero or more **Context Sources**.
@@ -67,6 +97,11 @@ The host-supplied environment overlay applied by the server when creating a PTY,
 - Changes from multiple **Context Sources** admitted at one safe boundary combine into one **Mid-Conversation System Message**.
 - Context changes are sampled and admitted lazily at a **Safe Provider-Turn Boundary**, never pushed asynchronously when their source changes.
 - At a **Safe Provider-Turn Boundary**, newly promoted user input or settled tool results precede any combined **Mid-Conversation System Message**.
+- An **Admitted Prompt** is replayable pending input, not yet model-visible **Session History**.
+- **Prompt Promotion** atomically consumes the pending inbox entry and appends its model-visible user message.
+- Steering prompts promote at the next **Safe Provider-Turn Boundary** while the current **Session Drain** still requires continuation. Promoting any newly admitted user input resets the selected agent's provider-turn allowance; multiple prompts promoted at one boundary reset it once.
+- A queued prompt does not promote while the current **Session Drain** requires continuation. The runner promotes one queued prompt when the Session would otherwise become idle, then reevaluates continuation before promoting another.
+- A **Session Drain** is process-local coordination rather than a durable domain entity. Durable recovery must reason from prompts, projected history, provider attempts, and tool state rather than inventing an enclosing execution identity.
 - The first provider turn renders the latest complete **Baseline System Context** and initializes its **Context Snapshot** without emitting a redundant **Mid-Conversation System Message**; unavailable initial context blocks the turn instead of persisting an incomplete baseline.
 - Initial **System Context** preparation precedes the first durable input promotion so an unavailable baseline leaves that input pending and retryable; ordinary reconciliation remains after promotion.
 - Compaction starts a new **Context Epoch** with a freshly rendered **Baseline System Context** and **Context Snapshot**; prior **Mid-Conversation System Messages** remain durable audit history but leave projected model history.
@@ -97,9 +132,56 @@ The host-supplied environment overlay applied by the server when creating a PTY,
 - A **Baseline System Context** durably preserves the exact joined text used for the active provider-cache prefix.
 - Completed compaction starts a new **Context Epoch** on the next provider attempt, folding the current complete **System Context** into a fresh baseline and removing earlier **Mid-Conversation System Messages** from active model history.
 - A model/provider switch preserves the current **Context Epoch** and chronological conversation history; the new selection applies to the next provider turn.
+- **Native Continuation Metadata** remains in durable history. Provider-turn projection includes it only for a successful exact originating provider/model match; failed turns and incompatible models omit opaque metadata, while non-empty visible reasoning lowers to ordinary assistant text after a model switch. This conservative relation may widen only when recorded provider tests establish compatibility.
 - **Model Request Options** remain provider-semantic through Catalog resolution. The Session runner maps them into the LLM package's provider-option namespace; the selected protocol adapter alone owns provider wire encoding.
 - **Generation Controls**, protocol-semantic **Model Request Options**, and compatibility request body fields are separate Catalog domains. A shared ingestion adapter partitions legacy and models.dev AI-SDK-shaped options before routing.
 - The **PTY Environment** is a server concern rather than a Core PTY concern. PTY creation merges caller values, then the host overlay, then Core-forced terminal invariants such as `TERM` and `OPENCODE_TERMINAL`.
+- Networked and **Embedded OpenCode** use the same **OpenCode Client** and preserve the full HTTP encoding, routing, middleware, and decoding boundary; only the `HttpClient` transport differs.
+- The Effect-native network constructor obtains `HttpClient.HttpClient` from its environment so callers own transport selection, recording, tracing, retries, and tests. Convenience runtimes may provide a fetch transport separately.
+- Creating **Embedded OpenCode** is scoped. Closing its owning Scope releases the in-process server resources, database resources, registrations, and fibers.
+- **Embedded OpenCode** exposes shared client capabilities and embedded-only capabilities on one object; consumers do not navigate through a nested `.client` property.
+- The beta **OpenCode Client** currently uses plural consumer-facing capability groups such as `sessions`; whether the stable Session namespace should instead be singular `session` must be settled before stabilization. Internal server identifiers do not implicitly define public client names.
+- Server's concrete `HttpApi` is authoritative for shared **OpenCode Client** capabilities. Codegen compiles its Session group directly; the Effect runtime uses an equivalent Protocol-only projection so generated artifacts remain independent of Core and Server.
+- SDK generation reflects the public `HttpApi` once into an **SDK Contract IR**. Promise and Effect emitters share endpoint structure and transport metadata without being required to expose identical public values: an emitter may select encoded wire types, decoded domain types, compile-time brands, runtime validation, and its own execution abstraction independently.
+- The first Effect emitter is the rich projection: it exposes decoded Effect-native values, preserves brands and schema transformations, performs runtime schema decoding, and delegates transport interpretation to `HttpApiClient`. Lighter wire-shaped Effect output remains possible through another emitter policy rather than constraining the shared IR.
+- The rich Effect emitter regenerates private executable schemas when the **SDK Contract IR** proves that their transport semantics can be reproduced exactly. Contracts with authoritative custom transformations use the import-based Effect emitter against a Protocol-only client projection whose generated transport output is tested against Server's concrete API; the Promise emitter still derives zero-Effect structural wire types from the same IR.
+- `@opencode-ai/protocol` owns Session endpoint construction and middleware placement. Server supplies concrete middleware keys to produce the authoritative build-time API; the client projection supplies transport-only keys without importing Core or Server at runtime.
+- The first Promise emitter targets the same clean domain-oriented method organization rather than Hey API source compatibility. It returns unwrapped values directly, rejects declared and infrastructure failures, and begins with minimal client-level transport configuration; result wrappers, interceptors, and legacy generated signatures are outside the initial surface.
+- The first Promise emitter parses response syntax and trusts its generated structural types; it does not perform runtime structural validation. Malformed payload syntax fails, while a syntactically valid shape mismatch is not detected at the SDK boundary. Standalone validator generation remains an optional future emitter policy.
+- Declared Promise-client failures retain their tagged structural wire values and have generated type guards. Consumers do not depend on generated `Error` subclass identity, preserving discrimination across package copies and realms while remaining structurally aligned with Effect domain errors.
+- Promise-client infrastructure failures use one generated `ClientError` class with a structured reason such as transport failure, unexpected status, unsupported content type, or malformed response. Promise methods reject with either a tagged declared domain failure or `ClientError`, matching the Effect client's conceptual domain/infrastructure error division.
+- Promise methods accept a separate optional per-call transport-options argument containing `AbortSignal` and header overrides. Cancellation and transport metadata do not enter the domain input object; broader interceptor and response-mode APIs remain deferred.
+- Promise streaming methods return a lazy `AsyncIterable` directly rather than a Promise-wrapped stream object. Iteration opens the connection, `AbortSignal` cancels it, and ending iteration closes the underlying request; the Effect emitter analogously returns `Stream` directly.
+- Promise SSE connection establishment, declared HTTP failures, and infrastructure failures occur during `AsyncIterable` iteration, beginning with its first `next()` call, rather than during synchronous method construction.
+- Neither generated streaming runtime automatically reconnects after disconnection. Promise `AsyncIterable` and Effect `Stream` fail explicitly; live consumers refresh and resubscribe, while durable sequence-based resume remains explicit composition above the generated client.
+- Promise client construction is synchronous and network-free. It requires `baseUrl`, defaults to `globalThis.fetch`, accepts client-level headers, and merges them with per-call header overrides.
+- Effect client construction accepts an explicit `baseUrl` and obtains `HttpClient.HttpClient` from the Effect environment. It does not install fetch or duplicate per-call transport policy; callers transform/provide the client for headers, tracing, retries, recording, and tests, while fiber interruption owns cancellation.
+- Promise and Effect emitters each own their generated public type modules. The **SDK Contract IR**, not a physically shared generated type package, is the common source; this permits zero-Effect wire types and rich decoded Effect types to evolve independently.
+- Promise and Effect network clients ship from `@opencode-ai/client` behind isolated root and `/effect` exports. The root has no runtime path to Effect; `/effect` imports only Effect, Schema, and Protocol.
+- The Effect-native scoped host belongs to `@opencode-ai/sdk-next`, which will assume the existing `@opencode-ai/sdk` name after legacy consumers migrate. Client remains network-only and SDK depends one-way on Client.
+- SDK executes Server's assembled `HttpRouter` in memory. It opens no listener and performs no network I/O, while preserving Server routing, middleware, codecs, handlers, and errors.
+- The Effect Client and SDK re-export their decoded datatype facade from Schema so callers do not depend on internal package locations or Core's versioned names.
+- A capability intended for both networked and **Embedded OpenCode** belongs in the authoritative public `HttpApi`; embedded-only same-process capabilities extend **Embedded OpenCode** separately.
+- `sessions.events({ sessionID, after })` is a public durable Session event stream. It verifies the Session, replays durable events after the optional aggregate sequence, continues with newly committed durable events, excludes live-only fragments, and is transported as SSE in both networked and embedded modes.
+- `events.subscribe()` is a distinct public instance-wide live stream for Session and non-Session activity. It has no replay guarantee and includes connection, heartbeat, and instance-disposal lifecycle events; consumers recover from disconnection by refreshing authoritative state.
+- A Session ID is not an optional filter on `events.subscribe()`: instance-wide live events and durable Session events have different schemas, replay guarantees, cursors, lifecycle events, and failure behavior.
+- The initial common OpenCode Client does not expose server-global event aggregation. `events.subscribe()` is bounded to the connected OpenCode instance or workspace; any future cross-instance administrative stream requires a separately designed API.
+- `events.subscribe()` does not automatically reconnect after transport loss. The live-only stream fails with `ClientError`; consumers refresh authoritative state before explicitly opening a new subscription because events missed during disconnection cannot be replayed.
+- `sessions.events({ sessionID, after })` returns the generated HTTP client's cold durable event stream and does not build reconnection policy into the endpoint or client constructor. Transport loss fails the stream with `ClientError`. Callers may compose an explicit resuming stream above it by retaining the last observed durable sequence and opening a new subscription with `after`; any reusable resume helper remains a separate API design question.
+- The stable `sessions.list(...)` design returns a **Page** in both networked and **Embedded OpenCode**; embedded execution does not define a separate unbounded array-returning list operation. The beta client currently preserves the existing HTTP `{ data, cursor }` envelope until emitter-level Page projection is implemented.
+- Session list cursors are opaque branded values carrying continuation query and ordering state. Consumers pass them back unchanged and do not inspect storage anchors or encoded filter fields.
+- A Session list continuation accepts only its opaque cursor. Scope, filters, ordering, and page size are fixed by the initial query and carried by that cursor.
+- `sessions.messages(...)` returns a **Page** and uses the same cursor discipline as `sessions.list(...)`: the initial request supplies `sessionID`, ordering, and page size; continuation supplies `sessionID` plus only an opaque branded message cursor carrying ordering, page size, direction, and message anchor. Using a cursor with another Session is invalid.
+- `sessions.message({ sessionID, messageID })` is a required resource lookup. An unknown Session fails with `SessionNotFoundError`; a known Session with an absent or differently owned message fails with `MessageNotFoundError` without disclosing cross-Session ownership. Absence is not represented as `undefined` across the public HTTP boundary.
+- `sessions.interrupt({ sessionID })` first verifies that the durable Session exists, failing with `SessionNotFoundError` otherwise. For a known Session, interruption is idempotent: idle, already-settled, or locally unowned execution is a no-op.
+- `sessions.active()` snapshots the current process's foreground Session drain registry as a record of Session IDs to `{ type: "running" }`. Missing IDs are inactive; background subagents and tasks do not make their parent Session active, and process restart clears the registry.
+- `sessions.context({ sessionID })` preserves the existing message-only operation. It returns projected conversational messages selected as Session context; it does not include or represent the complete provider request context, whose baseline system context and other contributions remain separate.
+- **Open question**: Should a future, separately named operation expose the complete provider request context, including baseline system context, selected source contributions, and context-epoch metadata?
+- `sessions.prompt(...)` exposes `resume?: boolean`. Omitting it preserves durable admission followed by an advisory execution wake; `resume: false` requests durable admit-only behavior.
+- The public operation remains `sessions.prompt(...)`; `SessionInput.admit` is the internal primitive, while the public `Admission` result and `resume` option express its durable admission semantics.
+- `sessions.create(...)` accepts an optional `location`. Omission resolves through the connected OpenCode instance's default or current location; an explicit value selects a known location. Networked and embedded transports use the same handler semantics.
+- `sessions.switchAgent({ sessionID, agent })` is part of the common client alongside `sessions.switchModel(...)`. It affects subsequent Session activity and fails with `SessionNotFoundError` for an unknown Session.
+- The **Embedded OpenCode** Layer delegates to the same scoped creation path; it does not define a second implementation.
 - A **PTY Environment** adapter observes plugins in the request Location while passing the resolved PTY working directory to the hook; standalone servers use an empty adapter.
 - A **Mid-Conversation System Message** lowers to the provider's native chronological instruction role when supported and to a wrapped chronological fallback otherwise.
 - When the effective aggregate instruction set changes, its **Mid-Conversation System Message** includes the complete current ordered set and supersedes the prior aggregate value; when no ambient instructions remain, the message states that previously loaded instructions no longer apply.
@@ -116,6 +198,23 @@ The host-supplied environment overlay applied by the server when creating a PTY,
 - **Managed Tool Output Files** use globally unique names in one shared flat directory. Their absolute paths are readable and searchable by ordinary tools; other absolute paths remain outside Location-scoped filesystem authority.
 - Provider-executed tool results remain provider-native transcript facts outside generic Tool Registry bounding. Their context control requires provider-aware pruning or compaction because some providers require exact structured round-trip payloads.
 
+## Client contract architecture
+
+Semantic values that mean the same thing internally and publicly live in the lightweight Schema leaf. Core consumes Schema for domain behavior; Protocol composes Schema values into paths, payloads, envelopes, errors, cursors, and streams; Server imports both, hosts Protocol's exact groups, and owns protocol/domain adaptation. The root Promise client remains zero-Effect, `/effect` depends on Effect plus Schema and Protocol, and `@opencode-ai/sdk-next` composes the scoped in-process host above Client, Core, and Server.
+
+Shared public records are plain objects declared with `Schema.Struct`. A same-name inferred interface gives object records readable TypeScript signatures without constructors, prototypes, or nominal identity; unions retain explicit type aliases.
+
+Before stabilizing the client API:
+
+- Keep additional public schemas in Schema and additional network groups in Protocol; neither package may transitively load databases, Drizzle, Session execution, providers, watchers, native modules, or WASM.
+- Keep concrete Location middleware keys in Server while Protocol owns their placement. Client projections may supply transport-only keys, but must prove generated equivalence with Server's concrete API.
+- Project the existing list response envelope to the stable client **Page** shape and enforce separate initial-query and cursor-continuation inputs without changing the hosted V2 wire contract.
+- Settle the stable consumer namespace (`session` versus the current beta `sessions`) and use an explicit codegen annotation if the consumer name should differ from the server group identifier.
+- Preserve V2 route paths, operation IDs, codecs, errors, middleware behavior, and OpenAPI output while making this change.
+- Preserve browser-safe `@opencode-ai/client` and `@opencode-ai/client/effect` bundles through import-boundary tests.
+- Define embedded-host placement before supporting multiple hosts over one database. Hosts that share durable Session storage must also share process-local Session execution coordination, or each host must receive isolated storage explicitly.
+- Keep an embedded request scope alive until any streamed response body finishes. The initial non-streaming Session surface does not exercise this lifetime boundary; Session and instance event streams must do so before joining the embedded client.
+
 ## Example dialogue
 
 > **Dev:** "The date changed while the session was active. Should the **Mid-Conversation System Message** say what the old date was?"

bun.lock

@@ -19,6 +19,7 @@
         "@typescript/native-preview": "catalog:",
         "glob": "13.0.5",
         "husky": "9.1.7",
+        "node-gyp": "12.4.0",
         "oxlint": "1.60.0",
         "oxlint-tsgolint": "0.21.0",
         "prettier": "3.6.2",
@@ -29,11 +30,17 @@
     },
     "packages/app": {
       "name": "@opencode-ai/app",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "dependencies": {
+        "@dnd-kit/abstract": "0.5.0",
+        "@dnd-kit/dom": "0.5.0",
+        "@dnd-kit/helpers": "0.5.0",
+        "@dnd-kit/solid": "0.5.0",
         "@kobalte/core": "catalog:",
         "@opencode-ai/core": "workspace:*",
+        "@opencode-ai/schema": "workspace:*",
         "@opencode-ai/sdk": "workspace:*",
+        "@opencode-ai/session-ui": "workspace:*",
         "@opencode-ai/ui": "workspace:*",
         "@pierre/trees": "1.0.0-beta.4",
         "@sentry/solid": "catalog:",
@@ -58,7 +65,7 @@
         "diff": "catalog:",
         "effect": "catalog:",
         "fuzzysort": "catalog:",
-        "ghostty-web": "github:anomalyco/ghostty-web#main",
+        "ghostty-web": "github:anomalyco/ghostty-web#513463a6f1190253057e8a3f0dac8f6ee8393553",
         "luxon": "catalog:",
         "marked": "catalog:",
         "marked-shiki": "catalog:",
@@ -78,6 +85,7 @@
         "@types/luxon": "catalog:",
         "@types/node": "catalog:",
         "@typescript/native-preview": "catalog:",
+        "tw-animate-css": "1.4.0",
         "typescript": "catalog:",
         "vite": "catalog:",
         "vite-plugin-icons-spritesheet": "3.0.1",
@@ -86,7 +94,7 @@
     },
     "packages/cli": {
       "name": "@opencode-ai/cli",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "bin": {
         "lildax": "./bin/lildax.cjs",
       },
@@ -109,9 +117,46 @@
         "@typescript/native-preview": "catalog:",
       },
     },
+    "packages/client": {
+      "name": "@opencode-ai/client",
+      "dependencies": {
+        "@opencode-ai/protocol": "workspace:*",
+        "@opencode-ai/schema": "workspace:*",
+      },
+      "devDependencies": {
+        "@effect/platform-node": "catalog:",
+        "@opencode-ai/core": "workspace:*",
+        "@opencode-ai/httpapi-codegen": "workspace:*",
+        "@opencode-ai/server": "workspace:*",
+        "@tsconfig/bun": "catalog:",
+        "@types/bun": "catalog:",
+        "@typescript/native-preview": "catalog:",
+        "effect": "catalog:",
+      },
+      "peerDependencies": {
+        "effect": "4.0.0-beta.83",
+      },
+      "optionalPeers": [
+        "effect",
+      ],
+    },
+    "packages/codemode": {
+      "name": "@opencode-ai/codemode",
+      "version": "0.0.1",
+      "dependencies": {
+        "acorn": "8.15.0",
+        "effect": "catalog:",
+        "typescript": "catalog:",
+      },
+      "devDependencies": {
+        "@tsconfig/bun": "catalog:",
+        "@types/bun": "catalog:",
+        "@typescript/native-preview": "catalog:",
+      },
+    },
     "packages/console/app": {
       "name": "@opencode-ai/console-app",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "dependencies": {
         "@cloudflare/vite-plugin": "1.15.2",
         "@ibm/plex": "6.4.1",
@@ -147,7 +192,7 @@
     },
     "packages/console/core": {
       "name": "@opencode-ai/console-core",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "dependencies": {
         "@aws-sdk/client-sts": "3.782.0",
         "@jsx-email/render": "1.1.1",
@@ -174,7 +219,7 @@
     },
     "packages/console/function": {
       "name": "@opencode-ai/console-function",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "dependencies": {
         "@ai-sdk/anthropic": "3.0.82",
         "@ai-sdk/openai": "3.0.48",
@@ -196,7 +241,7 @@
     },
     "packages/console/mail": {
       "name": "@opencode-ai/console-mail",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "dependencies": {
         "@jsx-email/all": "2.2.3",
         "@jsx-email/cli": "1.4.3",
@@ -220,7 +265,7 @@
     },
     "packages/console/support": {
       "name": "@opencode-ai/console-support",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "dependencies": {
         "@cloudflare/vite-plugin": "1.15.2",
         "@opencode-ai/console-core": "workspace:*",
@@ -240,7 +285,7 @@
     },
     "packages/core": {
       "name": "@opencode-ai/core",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "bin": {
         "opencode": "./bin/opencode",
       },
@@ -277,6 +322,7 @@
         "@opencode-ai/effect-sqlite-node": "workspace:*",
         "@opencode-ai/llm": "workspace:*",
         "@opencode-ai/plugin": "workspace:*",
+        "@opencode-ai/schema": "workspace:*",
         "@openrouter/ai-sdk-provider": "2.9.0",
         "@opentelemetry/api": "1.9.0",
         "@opentelemetry/context-async-hooks": "2.6.1",
@@ -287,10 +333,11 @@
         "ai-gateway-provider": "3.1.2",
         "bun-pty": "0.4.8",
         "cross-spawn": "catalog:",
+        "diff": "catalog:",
         "drizzle-orm": "catalog:",
         "effect": "catalog:",
         "fuzzysort": "3.1.0",
-        "gitlab-ai-provider": "6.9.3",
+        "gitlab-ai-provider": "6.10.0",
         "glob": "13.0.5",
         "google-auth-library": "10.5.0",
         "gray-matter": "4.0.3",
@@ -303,7 +350,7 @@
         "npm-package-arg": "13.0.2",
         "semver": "^7.6.3",
         "turndown": "7.2.0",
-        "venice-ai-sdk-provider": "2.0.2",
+        "venice-ai-sdk-provider": "2.1.1",
         "which": "6.0.1",
         "xdg-basedir": "5.1.0",
         "zod": "catalog:",
@@ -332,7 +379,7 @@
     },
     "packages/desktop": {
       "name": "@opencode-ai/desktop",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "dependencies": {
         "@zip.js/zip.js": "2.7.62",
         "effect": "catalog:",
@@ -386,7 +433,7 @@
     },
     "packages/effect-drizzle-sqlite": {
       "name": "@opencode-ai/effect-drizzle-sqlite",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "dependencies": {
         "drizzle-orm": "catalog:",
         "effect": "catalog:",
@@ -400,7 +447,7 @@
     },
     "packages/effect-sqlite-node": {
       "name": "@opencode-ai/effect-sqlite-node",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "dependencies": {
         "effect": "catalog:",
       },
@@ -412,10 +459,11 @@
     },
     "packages/enterprise": {
       "name": "@opencode-ai/enterprise",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "dependencies": {
         "@hono/standard-validator": "catalog:",
         "@opencode-ai/core": "workspace:*",
+        "@opencode-ai/session-ui": "workspace:*",
         "@opencode-ai/ui": "workspace:*",
         "@pierre/diffs": "catalog:",
         "@solidjs/meta": "catalog:",
@@ -443,7 +491,7 @@
     },
     "packages/function": {
       "name": "@opencode-ai/function",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "dependencies": {
         "@octokit/auth-app": "8.0.1",
         "@octokit/rest": "catalog:",
@@ -459,7 +507,7 @@
     },
     "packages/http-recorder": {
       "name": "@opencode-ai/http-recorder",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "dependencies": {
         "@effect/platform-node": "4.0.0-beta.83",
         "@effect/platform-node-shared": "4.0.0-beta.83",
@@ -476,10 +524,23 @@
         "effect": "4.0.0-beta.83",
       },
     },
+    "packages/httpapi-codegen": {
+      "name": "@opencode-ai/httpapi-codegen",
+      "dependencies": {
+        "effect": "catalog:",
+        "prettier": "3.6.2",
+      },
+      "devDependencies": {
+        "@tsconfig/bun": "catalog:",
+        "@types/bun": "catalog:",
+        "@typescript/native-preview": "catalog:",
+      },
+    },
     "packages/llm": {
       "name": "@opencode-ai/llm",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "dependencies": {
+        "@opencode-ai/schema": "workspace:*",
         "@smithy/eventstream-codec": "4.2.14",
         "@smithy/util-utf8": "4.2.2",
         "aws4fetch": "1.0.20",
@@ -496,7 +557,7 @@
     },
     "packages/opencode": {
       "name": "opencode",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "bin": {
         "opencode": "./bin/opencode",
       },
@@ -508,7 +569,7 @@
         "@ai-sdk/amazon-bedrock": "4.0.112",
         "@ai-sdk/anthropic": "3.0.82",
         "@ai-sdk/azure": "3.0.49",
-        "@ai-sdk/cerebras": "2.0.41",
+        "@ai-sdk/cerebras": "2.0.60",
         "@ai-sdk/cohere": "3.0.27",
         "@ai-sdk/deepinfra": "2.0.41",
         "@ai-sdk/gateway": "3.0.104",
@@ -533,8 +594,11 @@
         "@octokit/graphql": "9.0.2",
         "@octokit/rest": "catalog:",
         "@openauthjs/openauth": "catalog:",
+        "@opencode-ai/codemode": "workspace:*",
         "@opencode-ai/llm": "workspace:*",
         "@opencode-ai/plugin": "workspace:*",
+        "@opencode-ai/protocol": "workspace:*",
+        "@opencode-ai/schema": "workspace:*",
         "@opencode-ai/script": "workspace:*",
         "@opencode-ai/sdk": "workspace:*",
         "@opencode-ai/server": "workspace:*",
@@ -566,7 +630,7 @@
         "drizzle-orm": "catalog:",
         "effect": "catalog:",
         "fuzzysort": "3.1.0",
-        "gitlab-ai-provider": "6.9.3",
+        "gitlab-ai-provider": "6.10.0",
         "glob": "13.0.5",
         "google-auth-library": "10.5.0",
         "gray-matter": "4.0.3",
@@ -590,7 +654,7 @@
         "tree-sitter-powershell": "0.25.10",
         "turndown": "7.2.0",
         "ulid": "catalog:",
-        "venice-ai-sdk-provider": "2.0.2",
+        "venice-ai-sdk-provider": "2.1.1",
         "vscode-jsonrpc": "8.2.1",
         "web-tree-sitter": "0.25.10",
         "ws": "8.21.0",
@@ -624,7 +688,7 @@
     },
     "packages/plugin": {
       "name": "@opencode-ai/plugin",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "dependencies": {
         "@ai-sdk/provider": "3.0.8",
         "@opencode-ai/sdk": "workspace:*",
@@ -651,6 +715,29 @@
         "@opentui/solid",
       ],
     },
+    "packages/protocol": {
+      "name": "@opencode-ai/protocol",
+      "dependencies": {
+        "@opencode-ai/schema": "workspace:*",
+        "effect": "catalog:",
+      },
+      "devDependencies": {
+        "@tsconfig/bun": "catalog:",
+        "@types/bun": "catalog:",
+        "@typescript/native-preview": "catalog:",
+      },
+    },
+    "packages/schema": {
+      "name": "@opencode-ai/schema",
+      "dependencies": {
+        "effect": "catalog:",
+      },
+      "devDependencies": {
+        "@tsconfig/bun": "catalog:",
+        "@types/bun": "catalog:",
+        "@typescript/native-preview": "catalog:",
+      },
+    },
     "packages/script": {
       "name": "@opencode-ai/script",
       "dependencies": {
@@ -661,9 +748,23 @@
         "@types/semver": "^7.5.8",
       },
     },
+    "packages/sdk-next": {
+      "name": "@opencode-ai/sdk-next",
+      "dependencies": {
+        "@opencode-ai/client": "workspace:*",
+        "@opencode-ai/core": "workspace:*",
+        "@opencode-ai/server": "workspace:*",
+        "effect": "catalog:",
+      },
+      "devDependencies": {
+        "@tsconfig/bun": "catalog:",
+        "@types/bun": "catalog:",
+        "@typescript/native-preview": "catalog:",
+      },
+    },
     "packages/sdk/js": {
       "name": "@opencode-ai/sdk",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "dependencies": {
         "cross-spawn": "catalog:",
       },
@@ -678,9 +779,10 @@
     },
     "packages/server": {
       "name": "@opencode-ai/server",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "dependencies": {
         "@opencode-ai/core": "workspace:*",
+        "@opencode-ai/protocol": "workspace:*",
         "drizzle-orm": "catalog:",
         "effect": "catalog:",
       },
@@ -690,9 +792,53 @@
         "@typescript/native-preview": "catalog:",
       },
     },
+    "packages/session-ui": {
+      "name": "@opencode-ai/session-ui",
+      "version": "1.17.13",
+      "dependencies": {
+        "@kobalte/core": "catalog:",
+        "@opencode-ai/core": "workspace:*",
+        "@opencode-ai/sdk": "workspace:*",
+        "@opencode-ai/ui": "workspace:*",
+        "@pierre/diffs": "catalog:",
+        "@shikijs/stream": "catalog:",
+        "@shikijs/transformers": "3.9.2",
+        "@solid-primitives/bounds": "0.1.3",
+        "@solid-primitives/event-listener": "2.4.5",
+        "@solid-primitives/media": "2.3.3",
+        "@solid-primitives/resize-observer": "2.1.3",
+        "@solidjs/meta": "catalog:",
+        "@solidjs/router": "catalog:",
+        "diff": "catalog:",
+        "dompurify": "3.3.1",
+        "fuzzysort": "catalog:",
+        "katex": "0.16.27",
+        "luxon": "catalog:",
+        "marked": "catalog:",
+        "marked-katex-extension": "5.1.6",
+        "marked-shiki": "catalog:",
+        "morphdom": "2.7.8",
+        "motion": "12.34.5",
+        "remeda": "catalog:",
+        "remend": "catalog:",
+        "shiki": "catalog:",
+        "solid-js": "catalog:",
+        "solid-list": "catalog:",
+        "strip-ansi": "7.1.2",
+      },
+      "devDependencies": {
+        "@tsconfig/node22": "catalog:",
+        "@types/bun": "catalog:",
+        "@types/katex": "0.16.7",
+        "@types/luxon": "catalog:",
+        "@typescript/native-preview": "catalog:",
+        "typescript": "catalog:",
+        "vite": "catalog:",
+      },
+    },
     "packages/slack": {
       "name": "@opencode-ai/slack",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "dependencies": {
         "@opencode-ai/sdk": "workspace:*",
         "@slack/bolt": "^3.17.1",
@@ -705,7 +851,7 @@
     },
     "packages/stats/app": {
       "name": "@opencode-ai/stats-app",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "dependencies": {
         "@ibm/plex": "6.4.1",
         "@opencode-ai/stats-core": "workspace:*",
@@ -738,7 +884,7 @@
     },
     "packages/stats/core": {
       "name": "@opencode-ai/stats-core",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "dependencies": {
         "@aws-sdk/client-athena": "3.933.0",
         "@planetscale/database": "1.19.0",
@@ -757,7 +903,7 @@
     },
     "packages/stats/server": {
       "name": "@opencode-ai/stats-server",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "dependencies": {
         "@aws-sdk/client-firehose": "3.933.0",
         "@effect/platform-node": "catalog:",
@@ -776,6 +922,7 @@
     "packages/storybook": {
       "name": "@opencode-ai/storybook",
       "devDependencies": {
+        "@opencode-ai/session-ui": "workspace:*",
         "@opencode-ai/ui": "workspace:*",
         "@solidjs/meta": "catalog:",
         "@storybook/addon-a11y": "^10.2.13",
@@ -797,7 +944,7 @@
     },
     "packages/tui": {
       "name": "@opencode-ai/tui",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "dependencies": {
         "@opencode-ai/core": "workspace:*",
         "@opencode-ai/plugin": "workspace:*",
@@ -824,11 +971,9 @@
     },
     "packages/ui": {
       "name": "@opencode-ai/ui",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "dependencies": {
         "@kobalte/core": "catalog:",
-        "@opencode-ai/core": "workspace:*",
-        "@opencode-ai/sdk": "workspace:*",
         "@pierre/diffs": "catalog:",
         "@shikijs/stream": "catalog:",
         "@shikijs/transformers": "3.9.2",
@@ -836,8 +981,6 @@
         "@solid-primitives/event-listener": "2.4.5",
         "@solid-primitives/media": "2.3.3",
         "@solid-primitives/resize-observer": "2.1.3",
-        "@solidjs/meta": "catalog:",
-        "@solidjs/router": "catalog:",
         "diff": "catalog:",
         "dompurify": "3.3.1",
         "fuzzysort": "catalog:",
@@ -853,27 +996,33 @@
         "remeda": "catalog:",
         "remend": "catalog:",
         "shiki": "catalog:",
-        "solid-js": "catalog:",
         "solid-list": "catalog:",
         "strip-ansi": "7.1.2",
       },
       "devDependencies": {
+        "@solidjs/meta": "catalog:",
         "@tailwindcss/vite": "catalog:",
         "@tsconfig/node22": "catalog:",
         "@types/bun": "catalog:",
         "@types/katex": "0.16.7",
         "@types/luxon": "catalog:",
         "@typescript/native-preview": "catalog:",
+        "solid-js": "catalog:",
         "tailwindcss": "catalog:",
+        "tw-animate-css": "1.4.0",
         "typescript": "catalog:",
         "vite": "catalog:",
         "vite-plugin-icons-spritesheet": "3.0.1",
         "vite-plugin-solid": "catalog:",
       },
+      "peerDependencies": {
+        "@solidjs/meta": "^0.29.0",
+        "solid-js": "^1.9.0",
+      },
     },
     "packages/web": {
       "name": "@opencode-ai/web",
-      "version": "1.17.9",
+      "version": "1.17.13",
       "dependencies": {
         "@astrojs/cloudflare": "12.6.3",
         "@astrojs/markdown-remark": "6.3.1",
@@ -919,6 +1068,7 @@
     "@modelcontextprotocol/sdk@1.29.0": "patches/@modelcontextprotocol%2Fsdk@1.29.0.patch",
     "gcp-metadata@8.1.2": "patches/gcp-metadata@8.1.2.patch",
     "@standard-community/standard-openapi@0.2.9": "patches/@standard-community%2Fstandard-openapi@0.2.9.patch",
+    "effect@4.0.0-beta.83": "patches/effect@4.0.0-beta.83.patch",
     "@npmcli/agent@4.0.2": "patches/@npmcli%2Fagent@4.0.2.patch",
     "@silvia-odwyer/photon-node@0.3.4": "patches/@silvia-odwyer%2Fphoton-node@0.3.4.patch",
     "@tanstack/solid-virtual@3.13.28": "patches/@tanstack%2Fsolid-virtual@3.13.28.patch",
@@ -1326,6 +1476,20 @@
 
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+    "@dnd-kit/abstract": ["@dnd-kit/abstract@0.5.0", "", { "dependencies": { "@dnd-kit/geometry": "^0.5.0", "@dnd-kit/state": "^0.5.0", "tslib": "^2.6.2" } }, "sha512-hi13iMJgjPX/KDYVKg5VeDIhmYiV6buc9bAX+tCLYf4QdyYjPbsXjn2sPo6m7fQ6SGJBEFgHJ2PemeKDUbwBaA=="],
+
+    "@dnd-kit/collision": ["@dnd-kit/collision@0.5.0", "", { "dependencies": { "@dnd-kit/abstract": "^0.5.0", "@dnd-kit/geometry": "^0.5.0", "tslib": "^2.6.2" } }, "sha512-xUqRn3lS7oqLkT0AnnHS/STh/Czvwe1UapZFYiLbsUGxopMsQd4teaPCzPouOThoMdGEe+dHWjfqJl6t9iG4mQ=="],
+
+    "@dnd-kit/dom": ["@dnd-kit/dom@0.5.0", "", { "dependencies": { "@dnd-kit/abstract": "^0.5.0", "@dnd-kit/collision": "^0.5.0", "@dnd-kit/geometry": "^0.5.0", "@dnd-kit/state": "^0.5.0", "tslib": "^2.6.2" } }, "sha512-f2xFJp5SYQ8EW/Fbtaa8iBb66hpkWc7qa8vU826KW11/tb44sH+AisZnGtwOOTWTQ0GraqBDr5ixTErww+eKXw=="],
+
+    "@dnd-kit/geometry": ["@dnd-kit/geometry@0.5.0", "", { "dependencies": { "@dnd-kit/state": "^0.5.0", "tslib": "^2.6.2" } }, "sha512-ubHQS1CiSDH8ssYH2xG5BnpwPSFP1tStXXjug7/Ba6qnQdu/EUH47l6QXKIksQnnanfVfDf0aGeevRxgZlj28A=="],
+
+    "@dnd-kit/helpers": ["@dnd-kit/helpers@0.5.0", "", { "dependencies": { "@dnd-kit/abstract": "^0.5.0", "tslib": "^2.6.2" } }, "sha512-i4y+51/icSw+OHMr/su19qhnmNhAzh8PnBwXvapFYTd+64oodIyJRiRkB+hhfxAfnur7RYSW8qacDTrXjg2XOg=="],
+
+    "@dnd-kit/solid": ["@dnd-kit/solid@0.5.0", "", { "dependencies": { "@dnd-kit/abstract": "^0.5.0", "@dnd-kit/dom": "^0.5.0", "@dnd-kit/state": "^0.5.0", "tslib": "^2.6.2" }, "peerDependencies": { "solid-js": "^1.8.0" } }, "sha512-IKDqVZICS0jEeUzpJMIIF61w0WA4zisyx9U7K7Skbmkb/kQSDa3lB0cOc0947RwSO+ALoxytRNOuoNfyOIm3lQ=="],
+
+    "@dnd-kit/state": ["@dnd-kit/state@0.5.0", "", { "dependencies": { "@preact/signals-core": "^1.10.0", "tslib": "^2.6.2" } }, "sha512-y7XbabQqjF58Lk8YmDQuR8l6QjN+Kh4qlGEjUvHuIeasLk1QP+9L5diXS98VMxQIivyMmUtX2//f+3N7qPJX4w=="],
+
     "@dot/log": ["@dot/log@0.1.5", "", { "dependencies": { "chalk": "^4.1.2", "loglevelnext": "^6.0.0", "p-defer": "^3.0.0" } }, "sha512-ECraEVJWv2f2mWK93lYiefUkphStVlKD6yKDzisuoEmxuLKrxO9iGetHK2DoEAkj7sxjE886n0OUVVCUx0YPNg=="],
 
     "@drizzle-team/brocli": ["@drizzle-team/brocli@0.11.0", "", {}, "sha512-hD3pekGiPg0WPCCGAZmusBBJsDqGUR66Y452YgQsZOnkdQ7ViEPKuyP4huUGEZQefp8g34RRodXYmJ2TbCH+tg=="],
@@ -1774,6 +1938,10 @@
 
     "@opencode-ai/cli": ["@opencode-ai/cli@workspace:packages/cli"],
 
+    "@opencode-ai/client": ["@opencode-ai/client@workspace:packages/client"],
+
+    "@opencode-ai/codemode": ["@opencode-ai/codemode@workspace:packages/codemode"],
+
     "@opencode-ai/console-app": ["@opencode-ai/console-app@workspace:packages/console/app"],
 
     "@opencode-ai/console-core": ["@opencode-ai/console-core@workspace:packages/console/core"],
@@ -1800,16 +1968,26 @@
 
     "@opencode-ai/http-recorder": ["@opencode-ai/http-recorder@workspace:packages/http-recorder"],
 
+    "@opencode-ai/httpapi-codegen": ["@opencode-ai/httpapi-codegen@workspace:packages/httpapi-codegen"],
+
     "@opencode-ai/llm": ["@opencode-ai/llm@workspace:packages/llm"],
 
     "@opencode-ai/plugin": ["@opencode-ai/plugin@workspace:packages/plugin"],
 
+    "@opencode-ai/protocol": ["@opencode-ai/protocol@workspace:packages/protocol"],
+
+    "@opencode-ai/schema": ["@opencode-ai/schema@workspace:packages/schema"],
+
     "@opencode-ai/script": ["@opencode-ai/script@workspace:packages/script"],
 
     "@opencode-ai/sdk": ["@opencode-ai/sdk@workspace:packages/sdk/js"],
 
+    "@opencode-ai/sdk-next": ["@opencode-ai/sdk-next@workspace:packages/sdk-next"],
+
     "@opencode-ai/server": ["@opencode-ai/server@workspace:packages/server"],
 
+    "@opencode-ai/session-ui": ["@opencode-ai/session-ui@workspace:packages/session-ui"],
+
     "@opencode-ai/slack": ["@opencode-ai/slack@workspace:packages/slack"],
 
     "@opencode-ai/stats-app": ["@opencode-ai/stats-app@workspace:packages/stats/app"],
@@ -2150,6 +2328,8 @@
 
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+    "@preact/signals-core": ["@preact/signals-core@1.14.3", "", {}, "sha512-m0K3vnbSLC5rHs2ZVfeAMvBtT1zIyq4mxx5OlNncSgMj5Iz6W5Rn3kPrDxAC+iIKmiVe0lSl6U37t5ZkEWoVAw=="],
+
     "@protobuf-ts/plugin": ["@protobuf-ts/plugin@2.11.1", "", { "dependencies": { "@bufbuild/protobuf": "^2.4.0", "@bufbuild/protoplugin": "^2.4.0", "@protobuf-ts/protoc": "^2.11.1", "@protobuf-ts/runtime": "^2.11.1", "@protobuf-ts/runtime-rpc": "^2.11.1", "typescript": "^3.9" }, "bin": { "protoc-gen-ts": "bin/protoc-gen-ts", "protoc-gen-dump": "bin/protoc-gen-dump" } }, "sha512-HyuprDcw0bEEJqkOWe1rnXUP0gwYLij8YhPuZyZk6cJbIgc/Q0IFgoHQxOXNIXAcXM4Sbehh6kjVnCzasElw1A=="],
 
     "@protobuf-ts/protoc": ["@protobuf-ts/protoc@2.11.1", "", { "bin": { "protoc": "protoc.js" } }, "sha512-mUZJaV0daGO6HUX90o/atzQ6A7bbN2RSuHtdwo8SSF2Qoe3zHwa4IHyCN1evftTeHfLmdz+45qo47sL+5P8nyg=="],
@@ -2848,7 +3028,7 @@
 
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+    "acorn": ["acorn@8.15.0", "", { "bin": { "acorn": "bin/acorn" } }, "sha512-NZyJarBfL7nWwIq+FDL6Zp/yHEhePMNnnJ0y3qfieCrmNvYct8uvtiV41UvlSe6apAfk0fY1FbWx+NwfmpvtTg=="],
 
     "acorn-jsx": ["acorn-jsx@5.3.2", "", { "peerDependencies": { "acorn": "^6.0.0 || ^7.0.0 || ^8.0.0" } }, "sha512-rq9s+JNhf0IChjtDXxllJ7g41oZk5SlXtp0LHwyA5cejwn7vKmKp4pPri6YEePv2PU65sAsegbXtIinmDFDXgQ=="],
 
@@ -3420,7 +3600,7 @@
 
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+    "env-paths": ["env-paths@2.2.1", "", {}, "sha512-+h1lkLKhZMTYjog1VEpJNG7NZJWcuc2DDk/qsqSTRRCOXiLjeQ1d1/udrUGhqMxUgAlwKNZ0cf2uqan5GLuS2A=="],
 
     "err-code": ["err-code@2.0.3", "", {}, "sha512-2bmlRpNKBxT/CRmPOlyISQpNj+qSeYvcym/uT0Jx2bMOlKLtSy1ZmLuVxSEKKyor/N5yhvp/ZiG1oE3DEYMSFA=="],
 
@@ -3644,13 +3824,13 @@
 
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-    "ghostty-web": ["ghostty-web@github:anomalyco/ghostty-web#20bd361", {}, "anomalyco-ghostty-web-20bd361", "sha512-dW0nwaiBBcun9y5WJSvm3HxDLe5o9V0xLCndQvWonRVubU8CS1PHxZpLffyPt1YujPWC13ez03aWxcuKBPYYGQ=="],
+    "ghostty-web": ["ghostty-web@github:anomalyco/ghostty-web#513463a", {}, "anomalyco-ghostty-web-513463a", "sha512-GZR8LSmgGzViWnBJrqRI8MpAZRCJxhcr1Hi9Tyeh7YRooHZQjK9J97FQRD3tbBaM2wjq05gzGY2UEsG+JtZeBw=="],
 
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     "github-slugger": ["github-slugger@2.0.0", "", {}, "sha512-IaOQ9puYtjrkq7Y0Ygl9KDZnrf/aiUJYUpVf89y8kyaxbRG7Y1SrX/jaumrv81vc61+kiMempujsM3Yw7w5qcw=="],
 
-    "gitlab-ai-provider": ["gitlab-ai-provider@6.9.3", "", { "dependencies": { "@anthropic-ai/sdk": "^0.71.0", "@anycable/core": "^0.9.2", "graphql-request": "^6.1.0", "isomorphic-ws": "^5.0.0", "openai": "^6.16.0", "socket.io-client": "^4.8.1", "vscode-jsonrpc": "^8.2.1", "zod": "^3.25.76" }, "peerDependencies": { "@ai-sdk/provider": ">=3.0.0", "@ai-sdk/provider-utils": ">=4.0.0" } }, "sha512-lWo6b6es5+k9iXaDIvE9ECzyK4zfEza4+dQ5FN8SJpEuVRi3ZBCpHIOTa32QoYEDCBaiPh+tcyca86PfNodmlg=="],
+    "gitlab-ai-provider": ["gitlab-ai-provider@6.10.0", "", { "dependencies": { "@anthropic-ai/sdk": "^0.71.0", "@anycable/core": "^0.9.2", "graphql-request": "^6.1.0", "isomorphic-ws": "^5.0.0", "openai": "^6.16.0", "socket.io-client": "^4.8.1", "vscode-jsonrpc": "^8.2.1", "zod": "^3.25.76" }, "peerDependencies": { "@ai-sdk/provider": ">=3.0.0", "@ai-sdk/provider-utils": ">=4.0.0" } }, "sha512-oWEZ06rDO6JjB7INHO882wyBAQqCZVHiDHwCs5M+VPmdDj8TzhGXcYesA2CcV5RoI5lfHLKwGp5uKFB62VWpqw=="],
 
     "glob": ["glob@13.0.5", "", { "dependencies": { "minimatch": "^10.2.1", "minipass": "^7.1.2", "path-scurry": "^2.0.0" } }, "sha512-BzXxZg24Ibra1pbQ/zE7Kys4Ua1ks7Bn6pKLkVPZ9FZe4JQS6/Q7ef3LG1H+k7lUf5l4T3PLSyYyYJVYUvfgTw=="],
 
@@ -4342,7 +4522,7 @@
 
     "node-fetch-native": ["node-fetch-native@1.6.7", "", {}, "sha512-g9yhqoedzIUm0nTnTqAQvueMPVOuIY16bqgAJJC8XOOubYFNwz6IER9qs0Gq2Xd0+CecCKFjtdDTMA4u4xG06Q=="],
 
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+    "node-gyp": ["node-gyp@12.4.0", "", { "dependencies": { "env-paths": "^2.2.0", "exponential-backoff": "^3.1.1", "graceful-fs": "^4.2.6", "nopt": "^9.0.0", "proc-log": "^6.0.0", "semver": "^7.3.5", "tar": "^7.5.4", "tinyglobby": "^0.2.12", "undici": "^6.25.0", "which": "^6.0.0" }, "bin": { "node-gyp": "bin/node-gyp.js" } }, "sha512-OMcPNvqTCFUnNaBlmdgq+lfNqY7gTiSmNRDjY3uAXRyudeKZEZxu3CLtjMQrx4zZxCX2b/mpNqTtwuCJgXhHkw=="],
 
     "node-gyp-build": ["node-gyp-build@4.8.4", "", { "bin": { "node-gyp-build": "bin.js", "node-gyp-build-optional": "optional.js", "node-gyp-build-test": "build-test.js" } }, "sha512-LA4ZjwlnUblHVgq0oBF3Jl/6h/Nvs5fzBLwdEF4nuxnFdsfajde4WfxtJr3CaiH+F6ewcIB/q4jQ4UzPyid+CQ=="],
 
@@ -5158,6 +5338,8 @@
 
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+    "tw-animate-css": ["tw-animate-css@1.4.0", "", {}, "sha512-7bziOlRqH0hJx80h/3mbicLW7o8qLsH5+RaLR2t+OHM3D0JlWGODQKQ4cxbK7WlvmUxpcj6Kgu6EKqjrGFe3QQ=="],
+
     "tw-to-css": ["tw-to-css@0.0.12", "", { "dependencies": { "postcss": "8.4.31", "postcss-css-variables": "0.18.0", "tailwindcss": "3.3.2" } }, "sha512-rQAsQvOtV1lBkyCw+iypMygNHrShYAItES5r8fMsrhhaj5qrV2LkZyXc8ccEH+u5bFjHjQ9iuxe90I7Kykf6pw=="],
 
     "type-fest": ["type-fest@4.41.0", "", {}, "sha512-TeTSQ6H5YHvpqVwBRcnLDCBnDOHWYu7IvGbHT6N8AOymcr9PJGjc1GTtiWZTYg0NCgYwvnYWEkVChQAr9bjfwA=="],
@@ -5190,7 +5372,7 @@
 
     "uncrypto": ["uncrypto@0.1.3", "", {}, "sha512-Ql87qFHB3s/De2ClA9e0gsnS6zXG27SkTiSJwjCc9MebbfapQfuPzumMIUMi38ezPZVNFcHI9sUIepeQfw8J8Q=="],
 
-    "undici": ["undici@8.3.0", "", {}, "sha512-TkUDgb6tl7KOGZ+7e8E3d2FYgUQgF6z5YypqjWmixVQSQERFcVrVg0ySADm2LVLRh5ljAaHTCR5Fmz3Q34rB7Q=="],
+    "undici": ["undici@6.26.0", "", {}, "sha512-4yqz8a3n5HmGTlsbADNtr/dJlhkh/55Rq798G6ibiULcXbDtaLpTl1pvdqcbFfeoj3iSi52lePFM7h9H21cw/A=="],
 
     "undici-types": ["undici-types@7.16.0", "", {}, "sha512-Zz+aZWSj8LE6zoxD+xrjh4VfkIG8Ya6LvYkZqtUQGJPZjYl53ypCaUwWqo7eI0x66KBGeRo+mlBEkMSeSZ38Nw=="],
 
@@ -5266,7 +5448,7 @@
 
     "vary": ["vary@1.1.2", "", {}, "sha512-BNGbWLfd0eUPabhkXUVm0j8uuvREyTh5ovRa/dyow/BqAbZJyC+5fU+IzQOzmAKzYqYRAISoRhdQr3eIZ/PXqg=="],
 
-    "venice-ai-sdk-provider": ["venice-ai-sdk-provider@2.0.2", "", { "dependencies": { "@ai-sdk/openai-compatible": "^2.0.47", "@ai-sdk/provider": "^3.0.10", "@ai-sdk/provider-utils": "^4.0.27" }, "peerDependencies": { "ai": "^6.0.90" } }, "sha512-aoa05nI3BTK5aGbjBflq+Gfln2AHAkwNbWuGGvCzUIsOfp5Y3iPD4O4PUGDAEiWVJWbjpPn0KfDa0H/HebwsaA=="],
+    "venice-ai-sdk-provider": ["venice-ai-sdk-provider@2.1.1", "", { "dependencies": { "@ai-sdk/openai-compatible": "^2.0.51", "@ai-sdk/provider": "^3.0.10", "@ai-sdk/provider-utils": "^4.0.30" }, "peerDependencies": { "ai": "^6.0.90" } }, "sha512-w3OHkuzzKZ3r2TOxER6myBYzZJNoDqol+DUHu3NnfBN/GETnUVxecZJab0CHQQ8GZc0jjzpFymepjcLDPS4SQg=="],
 
     "verror": ["verror@1.10.1", "", { "dependencies": { "assert-plus": "^1.0.0", "core-util-is": "1.0.2", "extsprintf": "^1.2.0" } }, "sha512-veufcmxri4e3XSrT0xwfUR7kguIkaxBeosDg00yDWhk49wdwkSUrvvsm7nc75e1PUyvIeZj6nS8VQRYz2/S4Xg=="],
 
@@ -5392,7 +5574,7 @@
 
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-    "yallist": ["yallist@4.0.0", "", {}, "sha512-3wdGidZyq5PB084XLES5TpOSRA3wjXAlIWMhum2kRcv/41Sn2emQ0dycQW4uZXLejwKvg6EsvbdlVL+FYEct7A=="],
+    "yallist": ["yallist@5.0.0", "", {}, "sha512-YgvUTfwqyc7UXVMrB+SImsVYSmTS8X/tSrtdNZMImM+n7+QTriRXyXim0mBrTXNeqzVF0KWGgHPeiyViFFrNDw=="],
 
     "yaml": ["yaml@2.9.0", "", { "bin": { "yaml": "bin.mjs" } }, "sha512-2AvhNX3mb8zd6Zy7INTtSpl1F15HW6Wnqj0srWlkKLcpYl/gMIMJiyuGq2KeI2YFxUPjdlB+3Lc10seMLtL4cA=="],
 
@@ -5440,8 +5622,6 @@
 
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-    "@actions/http-client/undici": ["undici@6.26.0", "", {}, "sha512-4yqz8a3n5HmGTlsbADNtr/dJlhkh/55Rq798G6ibiULcXbDtaLpTl1pvdqcbFfeoj3iSi52lePFM7h9H21cw/A=="],
-
     "@ai-sdk/alibaba/@ai-sdk/openai-compatible": ["@ai-sdk/openai-compatible@2.0.41", "", { "dependencies": { "@ai-sdk/provider": "3.0.8", "@ai-sdk/provider-utils": "4.0.23" }, "peerDependencies": { "zod": "^3.25.76 || ^4.1.8" } }, "sha512-kNAGINk71AlOXx10Dq/PXw4t/9XjdK8uxfpVElRwtSFMdeSiLVt58p9TPx4/FJD+hxZuVhvxYj9r42osxWq79g=="],
 
     "@ai-sdk/amazon-bedrock/@ai-sdk/anthropic": ["@ai-sdk/anthropic@3.0.81", "", { "dependencies": { "@ai-sdk/provider": "3.0.10", "@ai-sdk/provider-utils": "4.0.27" }, "peerDependencies": { "zod": "^3.25.76 || ^4.1.8" } }, "sha512-B1JDd9Ugq9R5AgIaW3674lhGCMMYJcPUxnrZh8fzbGojgg4QvHFRv6eZahGQAUsmGHbcf74G9bdSBDLWQGY2GA=="],
@@ -5528,6 +5708,8 @@
 
     "@astrojs/mdx/@astrojs/markdown-remark": ["@astrojs/markdown-remark@6.3.11", "", { "dependencies": { "@astrojs/internal-helpers": "0.7.6", "@astrojs/prism": "3.3.0", "github-slugger": "^2.0.0", "hast-util-from-html": "^2.0.3", "hast-util-to-text": "^4.0.2", "import-meta-resolve": "^4.2.0", "js-yaml": "^4.1.1", "mdast-util-definitions": "^6.0.0", "rehype-raw": "^7.0.0", "rehype-stringify": "^10.0.1", "remark-gfm": "^4.0.1", "remark-parse": "^11.0.0", "remark-rehype": "^11.1.2", "remark-smartypants": "^3.0.2", "shiki": "^3.21.0", "smol-toml": "^1.6.0", "unified": "^11.0.5", "unist-util-remove-position": "^5.0.0", "unist-util-visit": "^5.0.0", "unist-util-visit-parents": "^6.0.2", "vfile": "^6.0.3" } }, "sha512-hcaxX/5aC6lQgHeGh1i+aauvSwIT6cfyFjKWvExYSxUhZZBBdvCliOtu06gbQyhbe0pGJNoNmqNlQZ5zYUuIyQ=="],
 
+    "@astrojs/mdx/acorn": ["acorn@8.16.0", "", { "bin": { "acorn": "bin/acorn" } }, "sha512-UVJyE9MttOsBQIDKw1skb9nAwQuR5wuGD3+82K6JgJlm/Y+KI92oNsMNGZCYdDsVtRHSak0pcV5Dno5+4jh9sw=="],
+
     "@astrojs/mdx/source-map": ["source-map@0.7.6", "", {}, "sha512-i5uvt8C3ikiWeNZSVZNWcfZPItFQOsYTUAOkcUPGd8DqDy1uOUikjt5dG+uRlwyvR108Fb9DOd4GvXfT0N2/uQ=="],
 
     "@astrojs/sitemap/zod": ["zod@4.4.3", "", {}, "sha512-ytENFjIJFl2UwYglde2jchW2Hwm4GJFLDiSXWdTrJQBIN9Fcyp7n4DhxJEiWNAJMV1/BqWfW/kkg71UDcHJyTQ=="],
@@ -5692,6 +5874,8 @@
 
     "@dot/log/chalk": ["chalk@4.1.2", "", { "dependencies": { "ansi-styles": "^4.1.0", "supports-color": "^7.1.0" } }, "sha512-oKnbhFyRIXpUuez8iBMmyEa4nbj4IOQyuhc/wy9kY7/WVPcwIO9VA668Pu8RkO7+0G76SLROeyw9CpQ061i4mA=="],
 
+    "@effect/platform-node/undici": ["undici@8.3.0", "", {}, "sha512-TkUDgb6tl7KOGZ+7e8E3d2FYgUQgF6z5YypqjWmixVQSQERFcVrVg0ySADm2LVLRh5ljAaHTCR5Fmz3Q34rB7Q=="],
+
     "@electron/asar/commander": ["commander@5.1.0", "", {}, "sha512-P0CysNDQ7rtVw4QIQtm+MRxV66vKFSvlsQvGYXZWR3qFU0jlMKHZZZgw8e+8DSah4UDKMqnknRDQz+xuQXQ/Zg=="],
 
     "@electron/asar/glob": ["glob@7.2.3", "", { "dependencies": { "fs.realpath": "^1.0.0", "inflight": "^1.0.4", "inherits": "2", "minimatch": "^3.1.1", "once": "^1.3.0", "path-is-absolute": "^1.0.0" } }, "sha512-nFR0zLpU2YCaRxwoCJvL6UvCH2JFyFVIvwTLsIf21AuHlMskA1hhTdk+LlYJtOlYt9v6dvszD2BGRqBL+iQK9Q=="],
@@ -5702,12 +5886,16 @@
 
     "@electron/fuses/fs-extra": ["fs-extra@9.1.0", "", { "dependencies": { "at-least-node": "^1.0.0", "graceful-fs": "^4.2.0", "jsonfile": "^6.0.1", "universalify": "^2.0.0" } }, "sha512-hcg3ZmepS30/7BSFqRvoo3DOMQu7IjqxO5nCDt+zM9XWjb33Wg7ziNT+Qvqbuc3+gWpzO02JubVyk2G4Zvo1OQ=="],
 
+    "@electron/get/env-paths": ["env-paths@3.0.0", "", {}, "sha512-dtJUTepzMW3Lm/NPxRf3wP4642UWhjL2sQxc+ym2YMj1m/H2zDNQOlezafzkHwn6sMstjHTwG6iQQsctDW/b1A=="],
+
     "@electron/get/undici": ["undici@7.26.0", "", {}, "sha512-3O9Tf67pGhgOv9jM35AbhkXAKi13f3oy3aE4CSgr+TckGeY+/iu97ZXN+J7DpHPzLbVApFd1IFhcnBjREYXYcg=="],
 
     "@electron/notarize/fs-extra": ["fs-extra@9.1.0", "", { "dependencies": { "at-least-node": "^1.0.0", "graceful-fs": "^4.2.0", "jsonfile": "^6.0.1", "universalify": "^2.0.0" } }, "sha512-hcg3ZmepS30/7BSFqRvoo3DOMQu7IjqxO5nCDt+zM9XWjb33Wg7ziNT+Qvqbuc3+gWpzO02JubVyk2G4Zvo1OQ=="],
 
     "@electron/osx-sign/isbinaryfile": ["isbinaryfile@4.0.10", "", {}, "sha512-iHrqe5shvBUcFbmZq9zOQHBoeOhZJu6RQGrDpBgenUm/Am+F3JM2MgQj+rK3Z601fzrL5gLZWtAPH2OBaSVcyw=="],
 
+    "@electron/rebuild/node-gyp": ["node-gyp@12.3.0", "", { "dependencies": { "env-paths": "^2.2.0", "exponential-backoff": "^3.1.1", "graceful-fs": "^4.2.6", "nopt": "^9.0.0", "proc-log": "^6.0.0", "semver": "^7.3.5", "tar": "^7.5.4", "tinyglobby": "^0.2.12", "undici": "^6.25.0", "which": "^6.0.0" }, "bin": { "node-gyp": "bin/node-gyp.js" } }, "sha512-QNcUWM+HgJplcPzBvFBZ9VXacyGZ4+VTOb80PwWR+TlVzoHbRKULNEzpRsnaoxG3Wzr7Qh7BYxGDU3CbKib2Yg=="],
+
     "@electron/universal/fs-extra": ["fs-extra@11.3.5", "", { "dependencies": { "graceful-fs": "^4.2.0", "jsonfile": "^6.0.1", "universalify": "^2.0.0" } }, "sha512-eKpRKAovdpZtR1WopLHxlBWvAgPny3c4gX1G5Jhwmmw4XJj0ifSD5qB5TOo8hmA0wlRKDAOAhEE1yVPgs6Fgcg=="],
 
     "@electron/universal/minimatch": ["minimatch@9.0.9", "", { "dependencies": { "brace-expansion": "^2.0.2" } }, "sha512-OBwBN9AL4dqmETlpS2zasx+vTeWclWzkblfZk7KTA5j3jeOONz/tRCnZomUyvNg83wL5Zv9Ss6HMJXAgL8R2Yg=="],
@@ -5738,6 +5926,8 @@
 
     "@malept/flatpak-bundler/fs-extra": ["fs-extra@9.1.0", "", { "dependencies": { "at-least-node": "^1.0.0", "graceful-fs": "^4.2.0", "jsonfile": "^6.0.1", "universalify": "^2.0.0" } }, "sha512-hcg3ZmepS30/7BSFqRvoo3DOMQu7IjqxO5nCDt+zM9XWjb33Wg7ziNT+Qvqbuc3+gWpzO02JubVyk2G4Zvo1OQ=="],
 
+    "@mdx-js/mdx/acorn": ["acorn@8.16.0", "", { "bin": { "acorn": "bin/acorn" } }, "sha512-UVJyE9MttOsBQIDKw1skb9nAwQuR5wuGD3+82K6JgJlm/Y+KI92oNsMNGZCYdDsVtRHSak0pcV5Dno5+4jh9sw=="],
+
     "@mdx-js/mdx/source-map": ["source-map@0.7.6", "", {}, "sha512-i5uvt8C3ikiWeNZSVZNWcfZPItFQOsYTUAOkcUPGd8DqDy1uOUikjt5dG+uRlwyvR108Fb9DOd4GvXfT0N2/uQ=="],
 
     "@modelcontextprotocol/sdk/express": ["express@5.2.1", "", { "dependencies": { "accepts": "^2.0.0", "body-parser": "^2.2.1", "content-disposition": "^1.0.0", "content-type": "^1.0.5", "cookie": "^0.7.1", "cookie-signature": "^1.2.1", "debug": "^4.4.0", "depd": "^2.0.0", "encodeurl": "^2.0.0", "escape-html": "^1.0.3", "etag": "^1.8.1", "finalhandler": "^2.1.0", "fresh": "^2.0.0", "http-errors": "^2.0.0", "merge-descriptors": "^2.0.0", "mime-types": "^3.0.0", "on-finished": "^2.4.1", "once": "^1.4.0", "parseurl": "^1.3.3", "proxy-addr": "^2.0.7", "qs": "^6.14.0", "range-parser": "^1.2.1", "router": "^2.2.0", "send": "^1.1.0", "serve-static": "^2.2.0", "statuses": "^2.0.1", "type-is": "^2.0.1", "vary": "^1.1.2" } }, "sha512-hIS4idWWai69NezIdRt2xFVofaF4j+6INOpJlVOLDO8zXGpUVEVzIYk12UUi2JzjEzWL3IOAxcTubgz9Po0yXw=="],
@@ -5756,6 +5946,8 @@
 
     "@npmcli/query/postcss-selector-parser": ["postcss-selector-parser@7.1.1", "", { "dependencies": { "cssesc": "^3.0.0", "util-deprecate": "^1.0.2" } }, "sha512-orRsuYpJVw8LdAwqqLykBj9ecS5/cRHlI5+nvTo8LcCKmzDmqVORXtOIYEEQuL9D4BxtA1lm5isAqzQZCoQ6Eg=="],
 
+    "@npmcli/run-script/node-gyp": ["node-gyp@12.3.0", "", { "dependencies": { "env-paths": "^2.2.0", "exponential-backoff": "^3.1.1", "graceful-fs": "^4.2.6", "nopt": "^9.0.0", "proc-log": "^6.0.0", "semver": "^7.3.5", "tar": "^7.5.4", "tinyglobby": "^0.2.12", "undici": "^6.25.0", "which": "^6.0.0" }, "bin": { "node-gyp": "bin/node-gyp.js" } }, "sha512-QNcUWM+HgJplcPzBvFBZ9VXacyGZ4+VTOb80PwWR+TlVzoHbRKULNEzpRsnaoxG3Wzr7Qh7BYxGDU3CbKib2Yg=="],
+
     "@octokit/auth-app/@octokit/request": ["@octokit/request@10.0.10", "", { "dependencies": { "@octokit/endpoint": "^11.0.3", "@octokit/request-error": "^7.0.2", "@octokit/types": "^16.0.0", "content-type": "^2.0.0", "json-with-bigint": "^3.5.3", "universal-user-agent": "^7.0.2" } }, "sha512-KxNC2pTqqhszMNrf12ZRd4PonRgyJdsM4F/jySiddQK+DsRcfBtUvqn8t7UsyZhnRJHvX46OohDt5N3VqIWC2w=="],
 
     "@octokit/auth-app/@octokit/request-error": ["@octokit/request-error@7.1.0", "", { "dependencies": { "@octokit/types": "^16.0.0" } }, "sha512-KMQIfq5sOPpkQYajXHwnhjCC0slzCNScLHs9JafXc4RAJI+9f+jNDlBNaIMTvazOPLgb4BnlhGJOTbnN0wIjPw=="],
@@ -5820,6 +6012,8 @@
 
     "@opencode-ai/core/@ai-sdk/openai-compatible": ["@ai-sdk/openai-compatible@2.0.41", "", { "dependencies": { "@ai-sdk/provider": "3.0.8", "@ai-sdk/provider-utils": "4.0.23" }, "peerDependencies": { "zod": "^3.25.76 || ^4.1.8" } }, "sha512-kNAGINk71AlOXx10Dq/PXw4t/9XjdK8uxfpVElRwtSFMdeSiLVt58p9TPx4/FJD+hxZuVhvxYj9r42osxWq79g=="],
 
+    "@opencode-ai/core/semver": ["semver@7.8.5", "", { "bin": { "semver": "bin/semver.js" } }, "sha512-Y7/KDsb8LjooZpwaqGyulO6DQlksgCncchHGk+sZIY4SBvUocMBEFH5Ur1fI4dV+Jvl0w6cjvucaIi40puRioA=="],
+
     "@opencode-ai/desktop/@actions/artifact": ["@actions/artifact@4.0.0", "", { "dependencies": { "@actions/core": "^1.10.0", "@actions/github": "^6.0.1", "@actions/http-client": "^2.1.0", "@azure/core-http": "^3.0.5", "@azure/storage-blob": "^12.15.0", "@octokit/core": "^5.2.1", "@octokit/plugin-request-log": "^1.0.4", "@octokit/plugin-retry": "^3.0.9", "@octokit/request": "^8.4.1", "@octokit/request-error": "^5.1.1", "@protobuf-ts/plugin": "^2.2.3-alpha.1", "archiver": "^7.0.1", "jwt-decode": "^3.1.2", "unzip-stream": "^0.3.1" } }, "sha512-HCc2jMJRAfviGFAh0FsOR/jNfWhirxl7W6z8zDtttt0GltwxBLdEIjLiweOPFl9WbyJRW1VWnPUSAixJqcWUMQ=="],
 
     "@opencode-ai/desktop/marked": ["marked@15.0.12", "", { "bin": { "marked": "bin/marked.js" } }, "sha512-8dD6FusOQSrpv9Z1rdNMdlSgQOIP880DHqnohobOmYLElGEqAL/JvxvuxZO16r4HtjTlfPRDC1hbvxC9dPN2nA=="],
@@ -5830,6 +6024,10 @@
 
     "@opencode-ai/llm/@smithy/util-utf8": ["@smithy/util-utf8@4.2.2", "", { "dependencies": { "@smithy/util-buffer-from": "^4.2.2", "tslib": "^2.6.2" } }, "sha512-75MeYpjdWRe8M5E3AW0O4Cx3UadweS+cwdXjwYGBW5h/gxxnbeZ877sLPX/ZJA9GVTlL/qG0dXP29JWFCD1Ayw=="],
 
+    "@opencode-ai/script/semver": ["semver@7.8.5", "", { "bin": { "semver": "bin/semver.js" } }, "sha512-Y7/KDsb8LjooZpwaqGyulO6DQlksgCncchHGk+sZIY4SBvUocMBEFH5Ur1fI4dV+Jvl0w6cjvucaIi40puRioA=="],
+
+    "@opencode-ai/session-ui/@solid-primitives/resize-observer": ["@solid-primitives/resize-observer@2.1.3", "", { "dependencies": { "@solid-primitives/event-listener": "^2.4.3", "@solid-primitives/rootless": "^1.5.2", "@solid-primitives/static-store": "^0.1.2", "@solid-primitives/utils": "^6.3.2" }, "peerDependencies": { "solid-js": "^1.6.12" } }, "sha512-zBLje5E06TgOg93S7rGPldmhDnouNGhvfZVKOp+oG2XU8snA+GoCSSCz1M+jpNAg5Ek2EakU5UVQqL152WmdXQ=="],
+
     "@opencode-ai/ui/@solid-primitives/resize-observer": ["@solid-primitives/resize-observer@2.1.3", "", { "dependencies": { "@solid-primitives/event-listener": "^2.4.3", "@solid-primitives/rootless": "^1.5.2", "@solid-primitives/static-store": "^0.1.2", "@solid-primitives/utils": "^6.3.2" }, "peerDependencies": { "solid-js": "^1.6.12" } }, "sha512-zBLje5E06TgOg93S7rGPldmhDnouNGhvfZVKOp+oG2XU8snA+GoCSSCz1M+jpNAg5Ek2EakU5UVQqL152WmdXQ=="],
 
     "@opencode-ai/web/@shikijs/transformers": ["@shikijs/transformers@3.20.0", "", { "dependencies": { "@shikijs/core": "3.20.0", "@shikijs/types": "3.20.0" } }, "sha512-PrHHMRr3Q5W1qB/42kJW6laqFyWdhrPF2hNR9qjOm1xcSiAO3hAHo7HaVyHE6pMyevmy3i51O8kuGGXC78uK3g=="],
@@ -5982,6 +6180,8 @@
 
     "astro/@astrojs/internal-helpers": ["@astrojs/internal-helpers@0.6.1", "", {}, "sha512-l5Pqf6uZu31aG+3Lv8nl/3s4DbUzdlxTWDof4pEpto6GUJNhhCbelVi9dEyurOVyqaelwmS9oSyOWOENSfgo9A=="],
 
+    "astro/acorn": ["acorn@8.16.0", "", { "bin": { "acorn": "bin/acorn" } }, "sha512-UVJyE9MttOsBQIDKw1skb9nAwQuR5wuGD3+82K6JgJlm/Y+KI92oNsMNGZCYdDsVtRHSak0pcV5Dno5+4jh9sw=="],
+
     "astro/common-ancestor-path": ["common-ancestor-path@1.0.1", "", {}, "sha512-L3sHRo1pXXEqX8VU28kfgUY+YGsk09hPqZiZmLacNib6XNTCM8ubYeT7ryXQw8asB1sKgcU5lkB7ONug08aB8w=="],
 
     "astro/diff": ["diff@5.2.2", "", {}, "sha512-vtcDfH3TOjP8UekytvnHH1o1P4FcUdt4eQ1Y+Abap1tk/OB2MWQvcwS2ClCd1zuIhc3JKOx6p3kod8Vfys3E+A=="],
@@ -6022,6 +6222,8 @@
 
     "conf/dot-prop": ["dot-prop@10.1.0", "", { "dependencies": { "type-fest": "^5.0.0" } }, "sha512-MVUtAugQMOff5RnBy2d9N31iG0lNwg1qAoAOn7pOK5wf94WIaE3My2p3uwTQuvS2AcqchkcR3bHByjaM0mmi7Q=="],
 
+    "conf/env-paths": ["env-paths@3.0.0", "", {}, "sha512-dtJUTepzMW3Lm/NPxRf3wP4642UWhjL2sQxc+ym2YMj1m/H2zDNQOlezafzkHwn6sMstjHTwG6iQQsctDW/b1A=="],
+
     "config-chain/ini": ["ini@1.3.8", "", {}, "sha512-JV/yugV2uzW5iMRSiZAyDtQd+nxtUnjeLt0acNdw98kKLrvuRVyB80tsREOE7yvGVgalhZ6RNXCmEHkUKBKxew=="],
 
     "crc/buffer": ["buffer@5.7.1", "", { "dependencies": { "base64-js": "^1.3.1", "ieee754": "^1.1.13" } }, "sha512-EHcyIPBQ4BSGlvjB16k5KgAJ27CIsHY/2JBmCRReo48y9rQ3MaUzWX3KVlBa4U7MyX02HdVj0K7C3WaB3ju7FQ=="],
@@ -6072,6 +6274,8 @@
 
     "engine.io-client/ws": ["ws@8.20.1", "", { "peerDependencies": { "bufferutil": "^4.0.1", "utf-8-validate": ">=5.0.2" }, "optionalPeers": ["bufferutil", "utf-8-validate"] }, "sha512-It4dO0K5v//JtTXuPkfEOaI3uUN87iYPnqo/ZzqCoG3g8uhA66QUMs/SrM0YK7/NAu+r4LMh/9dq2A7k+rHs+w=="],
 
+    "esast-util-from-js/acorn": ["acorn@8.16.0", "", { "bin": { "acorn": "bin/acorn" } }, "sha512-UVJyE9MttOsBQIDKw1skb9nAwQuR5wuGD3+82K6JgJlm/Y+KI92oNsMNGZCYdDsVtRHSak0pcV5Dno5+4jh9sw=="],
+
     "esbuild-plugin-copy/chalk": ["chalk@4.1.2", "", { "dependencies": { "ansi-styles": "^4.1.0", "supports-color": "^7.1.0" } }, "sha512-oKnbhFyRIXpUuez8iBMmyEa4nbj4IOQyuhc/wy9kY7/WVPcwIO9VA668Pu8RkO7+0G76SLROeyw9CpQ061i4mA=="],
 
     "esbuild-plugin-copy/chokidar": ["chokidar@3.6.0", "", { "dependencies": { "anymatch": "~3.1.2", "braces": "~3.0.2", "glob-parent": "~5.1.2", "is-binary-path": "~2.1.0", "is-glob": "~4.0.1", "normalize-path": "~3.0.0", "readdirp": "~3.6.0" }, "optionalDependencies": { "fsevents": "~2.3.2" } }, "sha512-7VT13fmjotKpGipCW9JEQAusEPE+Ei8nl6/g4FBAmIm0GOOLMua9NDDo/DWp0ZAxCr3cPq5ZpBqmPAQgDda2Pw=="],
@@ -6136,6 +6340,8 @@
 
     "md-to-react-email/marked": ["marked@7.0.4", "", { "bin": { "marked": "bin/marked.js" } }, "sha512-t8eP0dXRJMtMvBojtkcsA7n48BkauktUKzfkPSCq85ZMTJ0v76Rke4DYz01omYpPTUh4p/f7HePgRo3ebG8+QQ=="],
 
+    "micromark-extension-mdxjs/acorn": ["acorn@8.16.0", "", { "bin": { "acorn": "bin/acorn" } }, "sha512-UVJyE9MttOsBQIDKw1skb9nAwQuR5wuGD3+82K6JgJlm/Y+KI92oNsMNGZCYdDsVtRHSak0pcV5Dno5+4jh9sw=="],
+
     "micromatch/picomatch": ["picomatch@2.3.2", "", {}, "sha512-V7+vQEJ06Z+c5tSye8S+nHUfI51xoXIXjHQ99cQtKUkQqqO1kO/KCJUfZXuB47h/YBlDhah2H3hdUGXn8ie0oA=="],
 
     "miniflare/acorn": ["acorn@8.14.0", "", { "bin": { "acorn": "bin/acorn" } }, "sha512-cl669nCJTZBsL97OF4kUQm5g5hC2uihk0NxY3WENAC0TYdILVkAyHymAntgxGkl7K+t0cXIrH5siy5S4XkFycA=="],
@@ -6156,9 +6362,7 @@
 
     "nitro/undici": ["undici@7.26.0", "", {}, "sha512-3O9Tf67pGhgOv9jM35AbhkXAKi13f3oy3aE4CSgr+TckGeY+/iu97ZXN+J7DpHPzLbVApFd1IFhcnBjREYXYcg=="],
 
-    "node-gyp/env-paths": ["env-paths@2.2.1", "", {}, "sha512-+h1lkLKhZMTYjog1VEpJNG7NZJWcuc2DDk/qsqSTRRCOXiLjeQ1d1/udrUGhqMxUgAlwKNZ0cf2uqan5GLuS2A=="],
-
-    "node-gyp/undici": ["undici@6.26.0", "", {}, "sha512-4yqz8a3n5HmGTlsbADNtr/dJlhkh/55Rq798G6ibiULcXbDtaLpTl1pvdqcbFfeoj3iSi52lePFM7h9H21cw/A=="],
+    "node-gyp/semver": ["semver@7.8.5", "", { "bin": { "semver": "bin/semver.js" } }, "sha512-Y7/KDsb8LjooZpwaqGyulO6DQlksgCncchHGk+sZIY4SBvUocMBEFH5Ur1fI4dV+Jvl0w6cjvucaIi40puRioA=="],
 
     "node-gyp-build-optional-packages/detect-libc": ["detect-libc@2.1.2", "", {}, "sha512-Btj2BOOO83o3WyH59e8MgXsxEQVcarkUOpEYrubB0urwnN10yQ364rsiByU11nZlqWYZm05i/of7io4mzihBtQ=="],
 
@@ -6168,6 +6372,8 @@
 
     "nypm/tinyexec": ["tinyexec@1.2.4", "", {}, "sha512-SHf/r48b7vOrjve9PxJo3MN5v5yuyjHvdUcrQffT3WXMUfnGmHDVbC4k3sHJaJTgZCwpUplIaAo5ANtMyp3YHg=="],
 
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+
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@@ -6176,6 +6382,8 @@
 
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+    "opencode/semver": ["semver@7.8.5", "", { "bin": { "semver": "bin/semver.js" } }, "sha512-Y7/KDsb8LjooZpwaqGyulO6DQlksgCncchHGk+sZIY4SBvUocMBEFH5Ur1fI4dV+Jvl0w6cjvucaIi40puRioA=="],
+
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@@ -6258,7 +6466,7 @@
 
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@@ -6278,20 +6486,24 @@
 
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+
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+    "venice-ai-sdk-provider/@ai-sdk/openai-compatible": ["@ai-sdk/openai-compatible@2.0.53", "", { "dependencies": { "@ai-sdk/provider": "3.0.12", "@ai-sdk/provider-utils": "4.0.32" }, "peerDependencies": { "zod": "^3.25.76 || ^4.1.8" } }, "sha512-SoPSkrL5cbNQnAljRsJ7pOzJ2FmWgnhC0lfFOda873ycCdFJL1A+h3Ib7mX2spcv3XnNaO13y/45/0RyqNWlIQ=="],
 
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+    "venice-ai-sdk-provider/@ai-sdk/provider-utils": ["@ai-sdk/provider-utils@4.0.32", "", { "dependencies": { "@ai-sdk/provider": "3.0.12", "@standard-schema/spec": "^1.1.0", "eventsource-parser": "^3.0.8" }, "peerDependencies": { "zod": "^3.25.76 || ^4.1.8" } }, "sha512-Kwj499fTcN9bP/AfGoPU7JWIXeP6VZqKI6omsH062c9E2G4gdjeJczkz4z/tYSkzYjLE2AI3DtZbMfs6D7vn2Q=="],
 
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+    "vite-plugin-dynamic-import/acorn": ["acorn@8.16.0", "", { "bin": { "acorn": "bin/acorn" } }, "sha512-UVJyE9MttOsBQIDKw1skb9nAwQuR5wuGD3+82K6JgJlm/Y+KI92oNsMNGZCYdDsVtRHSak0pcV5Dno5+4jh9sw=="],
+
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     "vitest/@vitest/expect": ["@vitest/expect@4.1.7", "", { "dependencies": { "@standard-schema/spec": "^1.1.0", "@types/chai": "^5.2.2", "@vitest/spy": "4.1.7", "@vitest/utils": "4.1.7", "chai": "^6.2.2", "tinyrainbow": "^3.1.0" } }, "sha512-1R+tw0ortHEbZDGMymm+pN7/AFQ/RkFFdtd7EN+VBpynKmLbP8A3rpEXdshBJ7+8hQ9zBJh/i1s0yKNtxAnU7w=="],
@@ -6710,6 +6922,8 @@
 
     "@standard-community/standard-openapi/effect/@standard-schema/spec": ["@standard-schema/spec@1.1.0", "", {}, "sha512-l2aFy5jALhniG5HgqrD6jXLi/rUWrKvqN/qJx6yoJsgKhblVd+iqqU4RCXavm/jPityDo5TCvKMnpjKnOriy0w=="],
 
+    "@storybook/csf-plugin/unplugin/acorn": ["acorn@8.16.0", "", { "bin": { "acorn": "bin/acorn" } }, "sha512-UVJyE9MttOsBQIDKw1skb9nAwQuR5wuGD3+82K6JgJlm/Y+KI92oNsMNGZCYdDsVtRHSak0pcV5Dno5+4jh9sw=="],
+
     "@storybook/csf-plugin/unplugin/webpack-virtual-modules": ["webpack-virtual-modules@0.6.2", "", {}, "sha512-66/V2i5hQanC51vBQKPH4aI8NMAcBW59FVBs+rC7eGHupMyfn34q7rZIE+ETlJ+XTevqfUhVVBgSUNSW2flEUQ=="],
 
     "@tailwindcss/oxide-wasm32-wasi/@napi-rs/wasm-runtime/@tybys/wasm-util": ["@tybys/wasm-util@0.10.2", "", { "dependencies": { "tslib": "^2.4.0" } }, "sha512-RoBvJ2X0wuKlWFIjrwffGw1IqZHKQqzIchKaadZZfnNpsAYp2mM0h36JtPCjNDAHGgYez/15uMBpfGwchhiMgg=="],
@@ -6738,8 +6952,6 @@
 
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-    "app-builder-lib/@electron/get/env-paths": ["env-paths@2.2.1", "", {}, "sha512-+h1lkLKhZMTYjog1VEpJNG7NZJWcuc2DDk/qsqSTRRCOXiLjeQ1d1/udrUGhqMxUgAlwKNZ0cf2uqan5GLuS2A=="],
-
     "app-builder-lib/@electron/get/fs-extra": ["fs-extra@8.1.0", "", { "dependencies": { "graceful-fs": "^4.2.0", "jsonfile": "^4.0.0", "universalify": "^0.1.0" } }, "sha512-yhlQgA6mnOJUKOsRUFsgJdQCvkKhcz8tlZG5HBQfReYZy46OwLcY+Zia0mtdHsOo9y/hP+CxMN0TU9QxoOtG4g=="],
 
     "app-builder-lib/@electron/get/semver": ["semver@6.3.1", "", { "bin": { "semver": "bin/semver.js" } }, "sha512-BR7VvDCVHO+q2xBEWskxS6DJE1qRnb7DxzUrogb71CWoSficBxYsiAGd+Kl0mmq/MprG9yArRkyrQxTO6XjMzA=="],
@@ -6870,12 +7082,24 @@
 
     "lazystream/readable-stream/string_decoder": ["string_decoder@1.1.1", "", { "dependencies": { "safe-buffer": "~5.1.0" } }, "sha512-n/ShnvDi6FHbbVfviro+WojiFzv+s8MPMHBczVePfUpDJLwoLT0ht1l4YwBCbi8pJAveEEdnkHyPyTP/mzRfwg=="],
 
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+
+    "minipass-pipeline/minipass/yallist": ["yallist@4.0.0", "", {}, "sha512-3wdGidZyq5PB084XLES5TpOSRA3wjXAlIWMhum2kRcv/41Sn2emQ0dycQW4uZXLejwKvg6EsvbdlVL+FYEct7A=="],
+
     "motion/framer-motion/motion-dom": ["motion-dom@12.40.0", "", { "dependencies": { "motion-utils": "^12.39.0" } }, "sha512-HxU3ZaBwNPVQUBQf1xxgq+7JrPNZvjLVxgbpEZL7RrWJnsxOf0/OM+yrHG9ogLQ31Do/r57Oz2gQWPK+6q62mg=="],
 
     "motion/framer-motion/motion-utils": ["motion-utils@12.39.0", "", {}, "sha512-8nadJAJjTtqRkmRF36FoJTrywK9nnFmnPwnSMyxaOCU7GDjN9RTMJIxx9De8ErM+vpPhMccr/6fo5WciyQLnMQ=="],
 
     "opencode-gitlab-auth/open/wsl-utils": ["wsl-utils@0.1.0", "", { "dependencies": { "is-wsl": "^3.1.0" } }, "sha512-h3Fbisa2nKGPxCpm89Hk33lBLsnaGBvctQopaBSOW/uIs6FTe1ATyAnKFJrzVs9vpGdsTe73WF3V4lIsk4Gacw=="],
 
+    "opencode/@ai-sdk/cerebras/@ai-sdk/openai-compatible": ["@ai-sdk/openai-compatible@2.0.54", "", { "dependencies": { "@ai-sdk/provider": "3.0.12", "@ai-sdk/provider-utils": "4.0.33" }, "peerDependencies": { "zod": "^3.25.76 || ^4.1.8" } }, "sha512-OyXt0zK8y2/ZIyWlbxTv2r1M7AK227S+Gl4BYOEF42q0wz1n5m4fwR8L4Fy/MQ4Ho6xje47MPsFcRdIqIyP6Rw=="],
+
+    "opencode/@ai-sdk/cerebras/@ai-sdk/provider": ["@ai-sdk/provider@3.0.12", "", { "dependencies": { "json-schema": "^0.4.0" } }, "sha512-sj9DWTJ2Ze0WR9qsiOPqoqzNx3OxL6iMxHImbhvoe9qOspekbzxNDMiJ4TIGfYHYh9w4OmBjz3prvqhzTi96+Q=="],
+
+    "opencode/@ai-sdk/cerebras/@ai-sdk/provider-utils": ["@ai-sdk/provider-utils@4.0.33", "", { "dependencies": { "@ai-sdk/provider": "3.0.12", "@standard-schema/spec": "^1.1.0", "eventsource-parser": "^3.0.8" }, "peerDependencies": { "zod": "^3.25.76 || ^4.1.8" } }, "sha512-nJ0bAfegMAIJtrzMJtbzer1cS3nb7c7DsyU1S4nrPm7ZU0Mn6SBBZv5IGZZGTbpWTJwqKTSPeZJTXalbAxt1BA=="],
+
+    "openid-client/lru-cache/yallist": ["yallist@4.0.0", "", {}, "sha512-3wdGidZyq5PB084XLES5TpOSRA3wjXAlIWMhum2kRcv/41Sn2emQ0dycQW4uZXLejwKvg6EsvbdlVL+FYEct7A=="],
+
     "p-locate/p-limit/yocto-queue": ["yocto-queue@0.1.0", "", {}, "sha512-rVksvsnNCdJ/ohGc6xgPwyN8eheCxsiLM8mxuE/t/mOVqJewPuO1miLpTHQiRgTKCLexL4MeAFVagts7HmNZ2Q=="],
 
     "pkg-dir/find-up/locate-path": ["locate-path@5.0.0", "", { "dependencies": { "p-locate": "^4.1.0" } }, "sha512-t7hw9pI+WvuwNJXwk5zVHpyhIqzg2qTlklJOf0mVxGSbe3Fp2VieZcduNYjaLDoy6p9uGpQEGWG87WpMKlNq8g=="],
@@ -6908,6 +7132,10 @@
 
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+    "venice-ai-sdk-provider/@ai-sdk/openai-compatible/@ai-sdk/provider": ["@ai-sdk/provider@3.0.12", "", { "dependencies": { "json-schema": "^0.4.0" } }, "sha512-sj9DWTJ2Ze0WR9qsiOPqoqzNx3OxL6iMxHImbhvoe9qOspekbzxNDMiJ4TIGfYHYh9w4OmBjz3prvqhzTi96+Q=="],
+
+    "venice-ai-sdk-provider/@ai-sdk/provider-utils/@ai-sdk/provider": ["@ai-sdk/provider@3.0.12", "", { "dependencies": { "json-schema": "^0.4.0" } }, "sha512-sj9DWTJ2Ze0WR9qsiOPqoqzNx3OxL6iMxHImbhvoe9qOspekbzxNDMiJ4TIGfYHYh9w4OmBjz3prvqhzTi96+Q=="],
+
     "venice-ai-sdk-provider/@ai-sdk/provider-utils/@standard-schema/spec": ["@standard-schema/spec@1.1.0", "", {}, "sha512-l2aFy5jALhniG5HgqrD6jXLi/rUWrKvqN/qJx6yoJsgKhblVd+iqqU4RCXavm/jPityDo5TCvKMnpjKnOriy0w=="],
 
     "vitest/@vitest/expect/@standard-schema/spec": ["@standard-schema/spec@1.1.0", "", {}, "sha512-l2aFy5jALhniG5HgqrD6jXLi/rUWrKvqN/qJx6yoJsgKhblVd+iqqU4RCXavm/jPityDo5TCvKMnpjKnOriy0w=="],
@@ -7140,6 +7368,8 @@
 
     "app-builder-lib/@electron/get/fs-extra/universalify": ["universalify@0.1.2", "", {}, "sha512-rBJeI5CXAlmy1pV+617WB9J63U6XcazHHF2f2dbJix4XzpUF0RS3Zbj0FGIOCAva5P/d/GBOYaACQ1w+0azUkg=="],
 
+    "app-builder-lib/hosted-git-info/lru-cache/yallist": ["yallist@4.0.0", "", {}, "sha512-3wdGidZyq5PB084XLES5TpOSRA3wjXAlIWMhum2kRcv/41Sn2emQ0dycQW4uZXLejwKvg6EsvbdlVL+FYEct7A=="],
+
     "archiver-utils/glob/jackspeak/@isaacs/cliui": ["@isaacs/cliui@8.0.2", "", { "dependencies": { "string-width": "^5.1.2", "string-width-cjs": "npm:string-width@^4.2.0", "strip-ansi": "^7.0.1", "strip-ansi-cjs": "npm:strip-ansi@^6.0.1", "wrap-ansi": "^8.1.0", "wrap-ansi-cjs": "npm:wrap-ansi@^7.0.0" } }, "sha512-O8jcjabXaleOG9DQ0+ARXWZBTfnP4WNAqzuiJK7ll44AmxGKv/J2M4TPjxjY3znBCfvBXFzucm1twdyFybFqEA=="],
 
     "archiver-utils/glob/minimatch/brace-expansion": ["brace-expansion@2.1.1", "", { "dependencies": { "balanced-match": "^1.0.0" } }, "sha512-WR1cURNjuvBLMZBMbqM0UoE+WAfdUcEV1ccD8PVBVOI+Z3ND4+SZbN8RsfT2bMuG1qwz5RFvPukSZm5fF2D5eA=="],
@@ -7162,8 +7392,6 @@
 
     "editorconfig/minimatch/brace-expansion/balanced-match": ["balanced-match@1.0.2", "", {}, "sha512-3oSeUO0TMV67hN1AmbXsK4yaqU7tjiHlbxRDZOpH0KW9+CeX4bRAaX0Anxt0tx2MrpRpWwQaPwIlISEJhYU5Pw=="],
 
-    "electron-builder-squirrel-windows/app-builder-lib/@electron/get/env-paths": ["env-paths@2.2.1", "", {}, "sha512-+h1lkLKhZMTYjog1VEpJNG7NZJWcuc2DDk/qsqSTRRCOXiLjeQ1d1/udrUGhqMxUgAlwKNZ0cf2uqan5GLuS2A=="],
-
     "electron-builder-squirrel-windows/app-builder-lib/@electron/get/fs-extra": ["fs-extra@8.1.0", "", { "dependencies": { "graceful-fs": "^4.2.0", "jsonfile": "^4.0.0", "universalify": "^0.1.0" } }, "sha512-yhlQgA6mnOJUKOsRUFsgJdQCvkKhcz8tlZG5HBQfReYZy46OwLcY+Zia0mtdHsOo9y/hP+CxMN0TU9QxoOtG4g=="],
 
     "electron-builder-squirrel-windows/app-builder-lib/@electron/get/semver": ["semver@6.3.1", "", { "bin": { "semver": "bin/semver.js" } }, "sha512-BR7VvDCVHO+q2xBEWskxS6DJE1qRnb7DxzUrogb71CWoSficBxYsiAGd+Kl0mmq/MprG9yArRkyrQxTO6XjMzA=="],
@@ -7204,6 +7432,8 @@
 
     "js-beautify/glob/path-scurry/lru-cache": ["lru-cache@10.4.3", "", {}, "sha512-JNAzZcXrCt42VGLuYz0zfAzDfAvJWW6AfYlDBQyDV5DClI2m5sAmK+OIO7s59XfsRsWHp02jAJrRadPRGTt6SQ=="],
 
+    "opencode/@ai-sdk/cerebras/@ai-sdk/provider-utils/@standard-schema/spec": ["@standard-schema/spec@1.1.0", "", {}, "sha512-l2aFy5jALhniG5HgqrD6jXLi/rUWrKvqN/qJx6yoJsgKhblVd+iqqU4RCXavm/jPityDo5TCvKMnpjKnOriy0w=="],
+
     "pkg-dir/find-up/locate-path/p-locate": ["p-locate@4.1.0", "", { "dependencies": { "p-limit": "^2.2.0" } }, "sha512-R79ZZ/0wAxKGu3oYMlz8jy/kbhsNrS7SKZ7PxEHBgJ5+F2mtFW2fK2cOtBh1cHYkQsbzFV7I+EoRKe6Yt0oK7A=="],
 
     "pkg-up/find-up/locate-path/p-locate": ["p-locate@3.0.0", "", { "dependencies": { "p-limit": "^2.0.0" } }, "sha512-x+12w/To+4GFfgJhBEpiDcLozRJGegY+Ei7/z0tSLkMmxGZNybVMSfWj9aJn8Z5Fc7dBUNJOOVgPv2H7IwulSQ=="],
@@ -7270,6 +7500,8 @@
 
     "electron-builder-squirrel-windows/app-builder-lib/@electron/get/fs-extra/universalify": ["universalify@0.1.2", "", {}, "sha512-rBJeI5CXAlmy1pV+617WB9J63U6XcazHHF2f2dbJix4XzpUF0RS3Zbj0FGIOCAva5P/d/GBOYaACQ1w+0azUkg=="],
 
+    "electron-builder-squirrel-windows/app-builder-lib/hosted-git-info/lru-cache/yallist": ["yallist@4.0.0", "", {}, "sha512-3wdGidZyq5PB084XLES5TpOSRA3wjXAlIWMhum2kRcv/41Sn2emQ0dycQW4uZXLejwKvg6EsvbdlVL+FYEct7A=="],
+
     "electron-builder/yargs/cliui/strip-ansi/ansi-regex": ["ansi-regex@5.0.1", "", {}, "sha512-quJQXlTSUGL2LH9SUXo8VwsY4soanhgo6LNSm84E1LBcE8s3O0wpdiRzyR9z/ZZJMlMWv37qOOb9pdJlMUEKFQ=="],
 
     "electron-builder/yargs/string-width/strip-ansi/ansi-regex": ["ansi-regex@5.0.1", "", {}, "sha512-quJQXlTSUGL2LH9SUXo8VwsY4soanhgo6LNSm84E1LBcE8s3O0wpdiRzyR9z/ZZJMlMWv37qOOb9pdJlMUEKFQ=="],

infra/console.ts

@@ -256,6 +256,7 @@ new sst.cloudflare.x.SolidStart("Console", {
     SECRET.UpstashRedisRestToken,
     AUTH_API_URL,
     STRIPE_WEBHOOK_SECRET,
+    SECRET.SupportApiKey,
     DISCORD_INCIDENT_WEBHOOK_URL,
     SECRET.HoneycombWebhookSecret,
     STRIPE_SECRET_KEY,

infra/enterprise.ts

@@ -7,6 +7,7 @@ new sst.cloudflare.x.SolidStart("Teams", {
   domain: shortDomain,
   path: "packages/enterprise",
   buildCommand: "bun run build:cloudflare",
+  link: [SECRET.SupportApiKey],
   environment: {
     OPENCODE_STORAGE_ADAPTER: "r2",
     OPENCODE_STORAGE_ACCOUNT_ID: sst.cloudflare.DEFAULT_ACCOUNT_ID,

infra/secret.ts

@@ -9,6 +9,7 @@ export const SECRET = {
   R2SecretKey: new sst.Secret("R2SecretKey", "unknown"),
   HoneycombApiKey: new sst.Secret("HONEYCOMB_API_KEY"),
   HoneycombWebhookSecret: new random.RandomPassword("HoneycombWebhookSecret", { length: 24 }),
+  SupportApiKey: new sst.Secret("SUPPORT_API_KEY"),
   UpstashRedisRestUrl: new sst.Secret("UpstashRedisRestUrl"),
   UpstashRedisRestToken: new sst.Secret("UpstashRedisRestToken"),
 }

infra/stats.ts

@@ -42,11 +42,12 @@ const inferenceEventTable = new aws.s3tables.Table(
             { name: "request", type: "string", required: false },
             { name: "client", type: "string", required: false },
             { name: "user_agent", type: "string", required: false },
+            { name: "model", type: "string", required: false },
+            { name: "model_tier", type: "string", required: false },
             { name: "model_variant", type: "string", required: false },
             { name: "source", type: "string", required: false },
             { name: "provider", type: "string", required: false },
             { name: "provider_model", type: "string", required: false },
-            { name: "model", type: "string", required: false },
             { name: "llm_error_code", type: "int", required: false },
             { name: "llm_error_message", type: "string", required: false },
             { name: "error_response", type: "string", required: false },
@@ -56,6 +57,7 @@ const inferenceEventTable = new aws.s3tables.Table(
             { name: "error_cause2", type: "string", required: false },
             { name: "api_key", type: "string", required: false },
             { name: "workspace", type: "string", required: false },
+            { name: "user_id", type: "string", required: false },
             { name: "is_subscription", type: "boolean", required: false },
             { name: "subscription", type: "string", required: false },
             { name: "response_length", type: "long", required: false },
@@ -84,7 +86,7 @@ const inferenceEventTable = new aws.s3tables.Table(
       },
     },
   },
-  { deleteBeforeReplace: $app.stage !== "production" },
+  { deleteBeforeReplace: $app.stage !== "production", ignoreChanges: ["metadata"] },
 )
 
 export const inferenceEvent = new sst.Linkable("InferenceEvent", {

nix/hashes.json

@@ -1,8 +1,8 @@
 {
   "nodeModules": {
-    "x86_64-linux": "sha256-oWSGu+SP66Aquy/0Vaq7Bgp8404ZdOWbQX+O7h3jxHU=",
-    "aarch64-linux": "sha256-UsS0+c+GwtIukmWwQeFbY/3Oaz3t4Q7C6cFMGkmlyAY=",
-    "aarch64-darwin": "sha256-CArz92ewPmXO+ORFCBkCH8LzMpU/DjyaO4ic7QL0UpI=",
-    "x86_64-darwin": "sha256-rhnz9gmG6L06wIzfMhTaXDDEf6IbMD32CavqwXoqcUs="
+    "x86_64-linux": "sha256-ZmAIcG3wPgssKejLe/EMJOjPuMHCyRiiItRvSqIjaME=",
+    "aarch64-linux": "sha256-lbAHoVI/CvgdrfKZ/9dKZ/O7DxJvuWEOrDgcCuFGPBk=",
+    "aarch64-darwin": "sha256-Nrs4ijvzQ3J8AYigJSlsr66feUvLZ5iiYCfBdaZNJEc=",
+    "x86_64-darwin": "sha256-ltCaJSO7kZWuMOU49269xvboNVX35OJDFj0gXCDf62Y="
   }
 }

nix/opencode.nix

@@ -27,6 +27,13 @@ stdenvNoCC.mkDerivation (finalAttrs: {
     writableTmpDirAsHomeHook
   ];
 
+  postPatch = ''
+    # NOTE: Relax Bun version check to be a warning instead of an error
+    substituteInPlace packages/script/src/index.ts \
+      --replace-fail 'throw new Error(`This script requires bun@''${expectedBunVersionRange}' \
+                     'console.warn(`Warning: This script requires bun@''${expectedBunVersionRange}'
+  '';
+
   configurePhase = ''
     runHook preConfigure
 

package.json

@@ -99,6 +99,7 @@
     "@typescript/native-preview": "catalog:",
     "glob": "13.0.5",
     "husky": "9.1.7",
+    "node-gyp": "12.4.0",
     "oxlint": "1.60.0",
     "oxlint-tsgolint": "0.21.0",
     "prettier": "3.6.2",
@@ -153,6 +154,7 @@
     "@tanstack/solid-virtual@3.13.28": "patches/@tanstack%2Fsolid-virtual@3.13.28.patch",
     "@pierre/trees@1.0.0-beta.4": "patches/@pierre%2Ftrees@1.0.0-beta.4.patch",
     "@modelcontextprotocol/sdk@1.29.0": "patches/@modelcontextprotocol%2Fsdk@1.29.0.patch",
-    "@tanstack/virtual-core@3.17.0": "patches/@tanstack%2Fvirtual-core@3.17.0.patch"
+    "@tanstack/virtual-core@3.17.0": "patches/@tanstack%2Fvirtual-core@3.17.0.patch",
+    "effect@4.0.0-beta.83": "patches/effect@4.0.0-beta.83.patch"
   }
 }

packages/app/e2e/performance/README.md

@@ -18,6 +18,8 @@ bun run test:bench
 The suite contains:
 
 - cold and hot session-tab timing
+- home-session click timing split between content and titlebar-tab paint
+- single-session tab close timing through stable home restoration
 - cached session repaint and mutation tracing
 - streaming timeline throughput, RAF-gap, long-task, geometry, and remount diagnostics
 

packages/app/e2e/performance/timeline-stability/README.md

@@ -0,0 +1,61 @@
+# Timeline Layout Continuity
+
+Run from `packages/app`:
+
+```sh
+bun run test:stability
+```
+
+The suite runs a production build in one Chromium worker. Selected scenarios use deterministic 4x CPU stress after application readiness. This is a stress profile, not emulation of a specific device.
+
+## What It Proves
+
+The continuity probe samples DOM-derived layout and visibility state across browser render opportunities. Tests declare explicit contracts such as:
+
+- Preserve a visible semantic anchor while the user is away from the bottom.
+- Preserve end anchoring while active content grows or new content appears.
+- Keep adjacent visible rows ordered without material overlap.
+- Keep user-selected disclosure state through updates and virtualization.
+- Avoid a sampled blank interval while one visible surface replaces another.
+- Preserve logical row and control identity where local state or focus depends on it.
+- Keep keyboard, wheel, and nested-scroll ownership consistent during remeasurement.
+
+The suite exercises real browser reducer, projection, component, virtualizer, layout, focus, and interaction code. The backend and event producer are controlled fixtures.
+
+## What It Does Not Prove
+
+The pass/fail oracle does not inspect every compositor-presented pixel. A sample taken after `requestAnimationFrame` is a DOM/layout observation, not proof that every sampled state was displayed or that every displayed frame was sampled.
+
+The suite does not provide complete coverage for:
+
+- Compositor-only or raster-only glitches.
+- Color, contrast, canvas, WebGL, masks, irregular clips, or arbitrary occlusion.
+- Physical display refresh rates, native OS scaling, or a named low-end device.
+- TCP packetization, proxy buffering, or the complete real server/provider pipeline.
+
+Playwright video, trace, screenshots, and observation JSON are diagnostic evidence. They are not pixel baselines and do not participate in normal pass/fail decisions.
+
+For optional before/violation/after screenshots, set `OPENCODE_STABILITY_CAPTURE=1`. Capture is opt-in because compositor readback can perturb timing.
+
+## Test Layers
+
+- **Projection:** admitted rows, grouping, labels, and final visible states.
+- **Local state:** disclosure state, identity, duplicate delivery, and virtualization restoration.
+- **Interaction:** wheel, keyboard, nested scrolling, actionability, and focus behavior.
+- **Layout continuity:** anchoring, adjacency, responsive reflow, and visible surface handoffs.
+- **Reducer hardening:** validly shaped but intentionally reordered, duplicated, removed, or replaced events.
+- **Oracle contract:** pure analyzer and browser sampler calibration tests.
+
+Production-lifecycle fixtures should model states emitted by the current producer. Impossible or reordered sequences belong in reducer-hardening tests and must not be described as normal provider behavior.
+
+## Diagnostics
+
+Failures retain:
+
+- `video.webm`
+- `trace.zip`
+- failure screenshot
+- sampled DOM/layout trace JSON
+- event markers and summarized violations
+
+The analyzer records both unclipped layout bounds and ancestor-clipped visible intersections. Scrollbar and raw `scrollTop` changes alone do not fail continuity checks; user-visible semantic anchor movement does.

packages/app/e2e/performance/timeline-stability/adverse.spec.ts

@@ -0,0 +1,250 @@
+import { expect, test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import {
+  assistantMessage,
+  partUpdated,
+  setupTimeline,
+  shell,
+  textPart,
+  toolPart,
+  userMessage,
+  waitForVisualSettle,
+  type TimelineMessage,
+} from "./fixture"
+
+test.describe("timeline adverse visual stability", () => {
+  test("does not pull a scrolled-away user while an active shell grows", async ({ page }, testInfo) => {
+    const activeShellID = "prt_adverse_01_shell"
+    const messages = [
+      ...history(24),
+      userMessage(),
+      assistantMessage([shell(activeShellID, "running")], { completed: false }),
+    ]
+    const timeline = await setupTimeline(page, {
+      messages,
+      settings: { shellToolPartsExpanded: true },
+      cpuRate: 4,
+      eventRetry: 30,
+    })
+    const scroller = page.locator(".scroll-view__viewport", {
+      has: page.locator('[data-timeline-row="AssistantPart"]'),
+    })
+    await scroller.evaluate((element) => {
+      element.dispatchEvent(new WheelEvent("wheel", { bubbles: true, cancelable: true, deltaY: -450 }))
+      element.scrollTop = Math.max(0, element.scrollHeight - element.clientHeight - 450)
+    })
+    await page.waitForTimeout(150)
+    await expect
+      .poll(() => scroller.evaluate((element) => element.scrollHeight - element.clientHeight - element.scrollTop))
+      .toBeGreaterThan(100)
+    const anchor = await scroller.evaluate((element) => {
+      const view = element.getBoundingClientRect()
+      return [...element.querySelectorAll<HTMLElement>("[data-timeline-key]")].find((row) => {
+        const rect = row.getBoundingClientRect()
+        return rect.top >= view.top + 40 && rect.bottom <= view.bottom - 40
+      })?.dataset.timelineKey
+    })
+    expect(anchor).toBeTruthy()
+    await waitForVisualSettle(page, [`[data-timeline-key="${anchor}"]`])
+
+    const regions = defineVisualRegions({
+      anchor: { selector: `[data-timeline-key="${anchor}"]` },
+    })
+    await startVisualProbe(page, regions)
+    await timeline.send(partUpdated(shell(activeShellID, "running", lines(1))), 180)
+    await timeline.send(partUpdated(shell(activeShellID, "running", lines(10))), 90)
+    await timeline.send(partUpdated(shell(activeShellID, "running", lines(50))), 350)
+    await timeline.send(partUpdated(shell(activeShellID, "completed", lines(50))), 500)
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    await reportVisualStability(
+      testInfo,
+      "scrolled-away-shell",
+      trace,
+      visualPlan(regions, [
+        { type: "required", regions: ["anchor"] },
+        { type: "unique", regions: ["anchor"] },
+        { type: "stable", regions: ["anchor"] },
+        { type: "fixed", regions: ["anchor"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all", maxPositionReversals: 0 },
+        { type: "label-stability", regions: "all" },
+      ]),
+    )
+  })
+
+  test("preserves an explicit shell state across virtualization", async ({ page }) => {
+    const targetID = "prt_virtual_shell"
+    const messages = [
+      userMessage(undefined, { id: "msg_0000_virtual_user", created: 1700000000000 }),
+      assistantMessage([shell(targetID, "completed", lines(20))], {
+        id: "msg_0001_virtual_assistant",
+        parentID: "msg_0000_virtual_user",
+        created: 1700000001000,
+      }),
+      ...history(35, 10),
+    ]
+    await setupTimeline(page, { messages, settings: { shellToolPartsExpanded: false } })
+    const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
+    await scroller.evaluate((element) => {
+      element.dispatchEvent(new WheelEvent("wheel", { bubbles: true, cancelable: true, deltaY: -1_000 }))
+      element.scrollTop = 0
+    })
+    await page.waitForTimeout(300)
+    const trigger = page.locator(`[data-timeline-part-id="${targetID}"] [data-slot="collapsible-trigger"]`)
+    await expect(trigger).toBeVisible()
+    await trigger.click()
+    await expect(trigger).toHaveAttribute("aria-expanded", "true")
+
+    await scroller.evaluate((element) => (element.scrollTop = element.scrollHeight))
+    await expect(page.locator(`[data-timeline-part-id="${targetID}"]`)).toHaveCount(0)
+    await scroller.evaluate((element) => (element.scrollTop = 0))
+    await expect(trigger).toBeVisible()
+    await expect(trigger).toHaveAttribute("aria-expanded", "true")
+  })
+
+  test("keeps narrow viewport rows ordered during long shell growth", async ({ page }, testInfo) => {
+    const shellID = "prt_narrow_01_shell"
+    const followingID = "prt_narrow_02_following"
+    const timeline = await setupTimeline(page, {
+      messages: [
+        userMessage(),
+        assistantMessage(
+          [shell(shellID, "running"), textPart(followingID, "A narrow following row that wraps across lines.")],
+          {
+            completed: false,
+          },
+        ),
+      ],
+      settings: { shellToolPartsExpanded: true },
+      viewport: { width: 430, height: 800 },
+      cpuRate: 4,
+    })
+    await waitForVisualSettle(page, [
+      `[data-timeline-part-id="${shellID}"]`,
+      `[data-timeline-part-id="${followingID}"]`,
+    ])
+    const regions = defineVisualRegions({
+      shell: { selector: `[data-timeline-part-id="${shellID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+      following: {
+        selector: `[data-timeline-part-id="${followingID}"]`,
+        closest: '[data-timeline-row="AssistantPart"]',
+      },
+    })
+    await startVisualProbe(page, regions)
+    await timeline.send(partUpdated(shell(shellID, "running", wideLines(10))), 100)
+    await timeline.send(partUpdated(shell(shellID, "running", wideLines(50))), 300)
+    await timeline.send(partUpdated(shell(shellID, "completed", wideLines(50))), 500)
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    await reportVisualStability(
+      testInfo,
+      "narrow-shell",
+      trace,
+      visualPlan(
+        regions,
+        [
+          { type: "required", regions: ["shell", "following"] },
+          { type: "unique", regions: ["shell", "following"] },
+          { type: "stable", regions: ["shell", "following"] },
+          { type: "opacity", regions: "all" },
+          { type: "continuity", regions: "all" },
+          { type: "motion", regions: "all", maxPositionReversals: 0 },
+          { type: "label-stability", regions: "all" },
+          { type: "preserve-bottom-anchor" },
+          { type: "flow", regions: ["shell", "following"] },
+        ],
+        { perMarker: true },
+      ),
+    )
+  })
+
+  test("keeps visible rows ordered while resizing desktop to narrow and back", async ({ page }, testInfo) => {
+    const shellID = "prt_resize_01_shell"
+    const contextIDs = ["prt_resize_02_read", "prt_resize_03_glob"]
+    const followingID = "prt_resize_04_following"
+    await setupTimeline(page, {
+      messages: [
+        userMessage(),
+        assistantMessage([
+          shell(shellID, "completed", wideLines(15)),
+          toolPart(contextIDs[0]!, "read", "completed", { filePath: "src/a.ts" }),
+          toolPart(contextIDs[1]!, "glob", "completed", { path: ".", pattern: "**/*.ts" }),
+          textPart(followingID, "Following responsive timeline content that wraps on narrow screens."),
+        ]),
+      ],
+      settings: { shellToolPartsExpanded: true },
+      cpuRate: 4,
+      seedHistory: true,
+    })
+    const group = `[data-timeline-part-ids="${contextIDs.join(",")}"]`
+    const regions = defineVisualRegions({
+      shell: { selector: `[data-timeline-part-id="${shellID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+      context: { selector: group, closest: '[data-timeline-row="AssistantPart"]' },
+      following: {
+        selector: `[data-timeline-part-id="${followingID}"]`,
+        closest: '[data-timeline-row="AssistantPart"]',
+      },
+    })
+    await startVisualProbe(page, regions)
+    await page.setViewportSize({ width: 430, height: 800 })
+    await page.waitForTimeout(500)
+    await page.setViewportSize({ width: 900, height: 800 })
+    await page.waitForTimeout(500)
+    await page.setViewportSize({ width: 1400, height: 900 })
+    await page.waitForTimeout(500)
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    await reportVisualStability(
+      testInfo,
+      "responsive-resize",
+      trace,
+      visualPlan(regions, [
+        { type: "required", regions: ["shell", "context", "following"] },
+        { type: "unique", regions: ["shell", "context", "following"] },
+        { type: "stable", regions: ["shell", "context", "following"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all", maxPositionReversals: 4, maxReversals: 4 },
+        { type: "label-stability", regions: "all" },
+        { type: "flow", regions: ["shell", "context", "following"] },
+      ]),
+    )
+  })
+})
+
+function history(count: number, offset = 0): TimelineMessage[] {
+  return Array.from({ length: count }, (_, index) => {
+    const value = index + offset
+    const prefix = `msg_0${String(value).padStart(3, "0")}_history`
+    const userID = `${prefix}_a_user`
+    return [
+      userMessage(undefined, { id: userID, created: 1699990000000 + value * 10_000 }),
+      assistantMessage(
+        [
+          textPart(
+            `prt_history_${String(value).padStart(3, "0")}`,
+            `Historical response ${value}. ${"Stable history content. ".repeat(8)}`,
+          ),
+        ],
+        {
+          id: `${prefix}_b_assistant`,
+          parentID: userID,
+          created: 1699990001000 + value * 10_000,
+        },
+      ),
+    ]
+  }).flat()
+}
+
+function lines(count: number) {
+  return Array.from({ length: count }, (_, index) => `line ${index + 1}`).join("\n")
+}
+
+function wideLines(count: number) {
+  return Array.from({ length: count }, (_, index) => `line ${index + 1} ${"wide-output-".repeat(20)}`).join("\n")
+}

packages/app/e2e/performance/timeline-stability/context-matrix.spec.ts

@@ -0,0 +1,192 @@
+import { expect, test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import {
+  assistantID,
+  assistantMessage,
+  event,
+  partUpdated,
+  setupTimeline,
+  textPart,
+  toolPart,
+  userMessage,
+  waitForVisualSettle,
+} from "./fixture"
+
+const inputs = {
+  read: { filePath: "src/a.ts", offset: 0, limit: 120 },
+  glob: { path: ".", pattern: "**/*.ts" },
+  grep: { path: ".", pattern: "stable", include: "*.ts" },
+  list: { path: "src" },
+}
+
+test("appends context operations while the group is expanded", async ({ page }, testInfo) => {
+  const firstID = "prt_append_01_read"
+  const followingID = "prt_append_99_following"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([toolPart(firstID, "read", "running", inputs.read), textPart(followingID, "Following append")], {
+        completed: false,
+      }),
+    ],
+    cpuRate: 4,
+  })
+  const initialGroup = `[data-timeline-part-ids="${firstID}"]`
+  await page.locator(`${initialGroup} [data-slot="collapsible-trigger"]`).click()
+  await waitForVisualSettle(page, [initialGroup, `[data-timeline-part-id="${followingID}"]`])
+  const regions = defineVisualRegions({
+    context: {
+      selector: '[data-timeline-part-ids^="prt_append_01_read"]',
+      closest: '[data-timeline-row="AssistantPart"]',
+    },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(partUpdated(toolPart("prt_append_02_glob", "glob", "running", inputs.glob)), 180)
+  await timeline.send(partUpdated(toolPart("prt_append_03_grep", "grep", "completed", inputs.grep)), 240)
+  await timeline.send(partUpdated(toolPart("prt_append_04_list", "list", "completed", inputs.list)), 500)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "context-append",
+    trace,
+    visualPlan(
+      regions,
+      [
+        { type: "required", regions: ["context", "following"] },
+        { type: "unique", regions: ["context", "following"] },
+        { type: "stable", regions: ["context", "following"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: ["following"], maxPositionReversals: 0 },
+        { type: "label-stability", regions: "all" },
+        { type: "preserve-bottom-anchor" },
+        { type: "flow", regions: ["context", "following"] },
+      ],
+      { perMarker: true },
+    ),
+  )
+  await expect(
+    page.locator(
+      '[data-timeline-part-ids="prt_append_01_read,prt_append_02_glob,prt_append_03_grep,prt_append_04_list"]',
+    ),
+  ).toBeVisible()
+  await expect(
+    page.locator('[data-timeline-part-ids^="prt_append_01_read"] [data-slot="collapsible-trigger"]'),
+  ).toHaveAttribute("aria-expanded", "true")
+})
+
+test("splits and merges context groups when a middle text part changes", async ({ page }, testInfo) => {
+  const textID = "prt_split_02_text"
+  const followingID = "prt_split_99_following"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([
+        toolPart("prt_split_01_read", "read", "completed", inputs.read),
+        textPart(textID, "Boundary"),
+        toolPart("prt_split_03_glob", "glob", "completed", inputs.glob),
+        textPart(followingID, "Following split groups"),
+      ]),
+    ],
+    cpuRate: 4,
+  })
+  const regions = defineVisualRegions({
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(
+    event("message.part.removed", { sessionID: "ses_timeline_stability", messageID: assistantID, partID: textID }),
+    500,
+  )
+  await expect(page.locator('[data-timeline-part-ids="prt_split_01_read,prt_split_03_glob"]')).toBeVisible()
+  await timeline.send(partUpdated(textPart(textID, "Boundary restored")), 500)
+  await expect(page.locator('[data-timeline-part-ids="prt_split_01_read"]')).toBeVisible()
+  await expect(page.locator('[data-timeline-part-ids="prt_split_03_glob"]')).toBeVisible()
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "context-split-merge",
+    trace,
+    visualPlan(
+      regions,
+      [
+        { type: "required", regions: ["following"] },
+        { type: "unique", regions: ["following"] },
+        { type: "stable", regions: ["following"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all", maxPositionReversals: 1 },
+        { type: "label-stability", regions: "all" },
+      ],
+      { perMarker: true },
+    ),
+  )
+})
+
+test("removing the first context member replaces the group once without overlapping following content", async ({
+  page,
+}, testInfo) => {
+  const ids = ["prt_key_01_read", "prt_key_02_glob", "prt_key_03_grep"]
+  const followingID = "prt_key_99_following"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([
+        toolPart(ids[0]!, "read", "completed", inputs.read),
+        toolPart(ids[1]!, "glob", "completed", inputs.glob),
+        toolPart(ids[2]!, "grep", "completed", inputs.grep),
+        textPart(followingID, "Following replaced group"),
+      ]),
+    ],
+    cpuRate: 4,
+  })
+  const original = page.locator(`[data-timeline-part-ids="${ids.join(",")}"]`)
+  const originalRowKey = await original.evaluate((element) =>
+    element.closest("[data-timeline-key]")?.getAttribute("data-timeline-key"),
+  )
+  await original.locator('[data-slot="collapsible-trigger"]').click()
+  await expect(original.locator('[data-slot="collapsible-trigger"]')).toHaveAttribute("aria-expanded", "true")
+  const regions = defineVisualRegions({
+    context: {
+      selector: '[data-timeline-part-ids*="prt_key_02_glob"]',
+      closest: '[data-timeline-row="AssistantPart"]',
+    },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(
+    event("message.part.removed", { sessionID: "ses_timeline_stability", messageID: assistantID, partID: ids[0] }),
+    500,
+  )
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "context-first-remove",
+    trace,
+    visualPlan(regions, [
+      { type: "required", regions: ["context", "following"] },
+      { type: "unique", regions: ["context", "following"] },
+      { type: "opacity", regions: "all" },
+      { type: "continuity", regions: "all" },
+      { type: "motion", regions: "all", maxPositionReversals: 0 },
+      { type: "label-stability", regions: "all" },
+      { type: "flow", regions: ["context", "following"] },
+    ]),
+  )
+  await expect(page.locator(`[data-timeline-part-ids="${ids.slice(1).join(",")}"]`)).toBeVisible()
+  expect(
+    await page
+      .locator(`[data-timeline-part-ids="${ids.slice(1).join(",")}"]`)
+      .evaluate((element) => element.closest("[data-timeline-key]")?.getAttribute("data-timeline-key")),
+  ).toBe(originalRowKey)
+  await expect(
+    page.locator(`[data-timeline-part-ids="${ids.slice(1).join(",")}"] [data-slot="collapsible-trigger"]`),
+  ).toHaveAttribute("aria-expanded", "true")
+})

packages/app/e2e/performance/timeline-stability/environment-matrix.spec.ts

@@ -0,0 +1,113 @@
+import { test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import {
+  assistantMessage,
+  partUpdated,
+  setupTimeline,
+  shell,
+  textPart,
+  userMessage,
+  waitForVisualSettle,
+} from "./fixture"
+
+// Fractional scaling exercises different browser rounding than the baseline.
+for (const deviceScaleFactor of [1, 1.25]) {
+  test(`keeps shell growth ordered at device scale ${deviceScaleFactor}`, async ({ page }, testInfo) => {
+    const shellID = `prt_dpr_${String(deviceScaleFactor).replace(".", "_")}_01_shell`
+    const followingID = `prt_dpr_${String(deviceScaleFactor).replace(".", "_")}_02_following`
+    const timeline = await setupTimeline(page, {
+      messages: [
+        userMessage(),
+        assistantMessage([shell(shellID, "running"), textPart(followingID, "Following scaled shell")], {
+          completed: false,
+        }),
+      ],
+      settings: { shellToolPartsExpanded: true },
+      cpuRate: 4,
+      deviceScaleFactor,
+      seedHistory: true,
+    })
+    await waitForVisualSettle(page, [
+      `[data-timeline-part-id="${shellID}"]`,
+      `[data-timeline-part-id="${followingID}"]`,
+    ])
+    const regions = defineVisualRegions({
+      shell: { selector: `[data-timeline-part-id="${shellID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+      following: {
+        selector: `[data-timeline-part-id="${followingID}"]`,
+        closest: '[data-timeline-row="AssistantPart"]',
+      },
+    })
+    await startVisualProbe(page, regions)
+    await timeline.send(partUpdated(shell(shellID, "running", lines(20))), 180)
+    await timeline.send(partUpdated(shell(shellID, "completed", lines(20))), 500)
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    await reportVisualStability(testInfo, `dpr-${deviceScaleFactor}`, trace, shellPlan(regions))
+  })
+}
+
+for (const reducedMotion of [true]) {
+  test(`keeps shell and status transitions ordered with reduced motion ${reducedMotion}`, async ({
+    page,
+  }, testInfo) => {
+    const shellID = `prt_motion_${reducedMotion}_01_shell`
+    const followingID = `prt_motion_${reducedMotion}_02_following`
+    const timeline = await setupTimeline(page, {
+      messages: [
+        userMessage(),
+        assistantMessage([shell(shellID, "running"), textPart(followingID, "Following motion profile")], {
+          completed: false,
+        }),
+      ],
+      settings: { shellToolPartsExpanded: true },
+      reducedMotion,
+      cpuRate: 4,
+      seedHistory: true,
+    })
+    await waitForVisualSettle(page, [
+      `[data-timeline-part-id="${shellID}"]`,
+      `[data-timeline-part-id="${followingID}"]`,
+    ])
+    const regions = defineVisualRegions({
+      shell: { selector: `[data-timeline-part-id="${shellID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+      following: {
+        selector: `[data-timeline-part-id="${followingID}"]`,
+        closest: '[data-timeline-row="AssistantPart"]',
+      },
+    })
+    await startVisualProbe(page, regions)
+    await timeline.send(partUpdated(shell(shellID, "completed", lines(10))), 500)
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    await reportVisualStability(testInfo, `reduced-motion-${reducedMotion}`, trace, shellPlan(regions))
+  })
+}
+
+function lines(count: number) {
+  return Array.from({ length: count }, (_, index) => `line ${index + 1}`).join("\n")
+}
+
+function shellPlan<Regions extends ReturnType<typeof defineVisualRegions>>(
+  regions: Regions & Record<"shell" | "following", { selector: string }>,
+) {
+  return visualPlan(
+    regions,
+    [
+      { type: "required", regions: ["shell", "following"] },
+      { type: "unique", regions: ["shell", "following"] },
+      { type: "stable", regions: ["shell", "following"] },
+      { type: "opacity", regions: "all" },
+      { type: "continuity", regions: "all" },
+      { type: "motion", regions: "all", maxPositionReversals: 0 },
+      { type: "label-stability", regions: "all" },
+      { type: "preserve-bottom-anchor" },
+      { type: "flow", regions: ["shell", "following"] },
+    ],
+    { perMarker: true },
+  )
+}

packages/app/e2e/performance/timeline-stability/file-matrix.spec.ts

@@ -0,0 +1,121 @@
+import { test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import {
+  assistantMessage,
+  partUpdated,
+  setupTimeline,
+  textPart,
+  toolPart,
+  userMessage,
+  waitForVisualSettle,
+} from "./fixture"
+
+const profiles = [
+  { name: "edit", tool: "edit", input: { filePath: "src/edit.ts" } },
+  {
+    name: "multi patch",
+    tool: "apply_patch",
+    input: { files: ["src/a.ts", "src/b.ts", "src/old.ts", "src/moved.ts"] },
+  },
+] as const
+
+for (const profile of profiles) {
+  test(`stabilizes ${profile.name} pending to completed`, async ({ page }, testInfo) => {
+    const partID = `prt_file_matrix_${profiles.indexOf(profile)}`
+    const followingID = `prt_file_matrix_following_${profiles.indexOf(profile)}`
+    const timeline = await setupTimeline(page, {
+      messages: [
+        userMessage(),
+        assistantMessage(
+          [
+            toolPart(partID, profile.tool, "pending", profile.input),
+            textPart(followingID, `Following ${profile.name}`),
+          ],
+          { completed: false },
+        ),
+      ],
+      settings: { editToolPartsExpanded: true },
+      cpuRate: 4,
+    })
+    await waitForVisualSettle(page, [`[data-timeline-part-id="${partID}"]`, `[data-timeline-part-id="${followingID}"]`])
+    const regions = defineVisualRegions({
+      tool: { selector: `[data-timeline-part-id="${partID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+      following: {
+        selector: `[data-timeline-part-id="${followingID}"]`,
+        closest: '[data-timeline-row="AssistantPart"]',
+      },
+    })
+    await startVisualProbe(page, regions)
+    await timeline.send(partUpdated(toolPart(partID, profile.tool, "running", profile.input)), 180)
+    await timeline.send(partUpdated(completedPart(partID, profile)), 900)
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    await reportVisualStability(
+      testInfo,
+      `file-${profile.name}`,
+      trace,
+      visualPlan(
+        regions,
+        [
+          { type: "required", regions: ["tool", "following"] },
+          { type: "unique", regions: ["tool", "following"] },
+          { type: "stable", regions: ["tool", "following"] },
+          { type: "opacity", regions: "all" },
+          { type: "continuity", regions: "all" },
+          { type: "motion", regions: "all", maxPositionReversals: 0, maxReversals: 1 },
+          { type: "label-stability", regions: "all" },
+          { type: "preserve-bottom-anchor" },
+          { type: "flow", regions: ["tool", "following"] },
+        ],
+        { perMarker: true },
+      ),
+    )
+  })
+}
+
+function completedPart(partID: string, profile: (typeof profiles)[number]) {
+  if (profile.tool === "edit") {
+    return toolPart(partID, profile.tool, "completed", profile.input, {
+      metadata: {
+        filediff: {
+          file: "src/edit.ts",
+          additions: 50,
+          deletions: 50,
+          before: source(50, false),
+          after: source(50, true),
+        },
+      },
+    })
+  }
+  const files = [
+    patchFile("src/a.ts", "update"),
+    patchFile("src/b.ts", "add"),
+    patchFile("src/old.ts", "delete"),
+    { ...patchFile("src/moved.ts", "move"), move: "src/new-place.ts" },
+  ]
+  return toolPart(partID, profile.tool, "completed", profile.input, { metadata: { files } })
+}
+
+function patchFile(filePath: string, type: "add" | "update" | "delete" | "move") {
+  return {
+    filePath,
+    relativePath: filePath,
+    type,
+    additions: type === "delete" ? 0 : 20,
+    deletions: type === "add" ? 0 : 20,
+    before: type === "add" ? undefined : source(20, false),
+    after: type === "delete" ? undefined : source(20, true),
+  }
+}
+
+function source(count: number, changed: boolean) {
+  return Array.from(
+    { length: count },
+    (_, index) => `export const value${index} = ${changed ? index + 1 : index}\n`,
+  ).join("")
+}

packages/app/e2e/performance/timeline-stability/file-mutation.spec.ts

@@ -0,0 +1,113 @@
+import { expect, test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import {
+  assistantMessage,
+  partUpdated,
+  setupTimeline,
+  textPart,
+  toolPart,
+  userMessage,
+  waitForVisualSettle,
+} from "./fixture"
+
+test("adds patch files incrementally without resetting outer expansion", async ({ page }, testInfo) => {
+  const patchID = "prt_incremental_01_patch"
+  const followingID = "prt_incremental_02_following"
+  const first = patchFile("src/a.ts", "update")
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage(
+        [
+          toolPart(patchID, "apply_patch", "running", { files: [first.filePath] }, { metadata: { files: [first] } }),
+          textPart(followingID, "Following incremental patch"),
+        ],
+        { completed: false },
+      ),
+    ],
+    settings: { editToolPartsExpanded: true },
+    cpuRate: 4,
+    seedHistory: true,
+  })
+  const trigger = page.locator(`[data-timeline-part-id="${patchID}"] [data-slot="collapsible-trigger"]`).first()
+  await expect(trigger).toHaveAttribute("aria-expanded", "true")
+  await waitForVisualSettle(page, [`[data-timeline-part-id="${patchID}"]`, `[data-timeline-part-id="${followingID}"]`])
+  const regions = defineVisualRegions({
+    patch: { selector: `[data-timeline-part-id="${patchID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  const second = patchFile("src/b.ts", "add")
+  const third = patchFile("src/old.ts", "delete")
+  await timeline.send(
+    partUpdated(
+      toolPart(
+        patchID,
+        "apply_patch",
+        "running",
+        { files: [first.filePath, second.filePath] },
+        { metadata: { files: [first, second] } },
+      ),
+    ),
+    240,
+  )
+  await timeline.send(
+    partUpdated(
+      toolPart(
+        patchID,
+        "apply_patch",
+        "completed",
+        { files: [first.filePath, second.filePath, third.filePath] },
+        { metadata: { files: [first, second, third] } },
+      ),
+    ),
+    800,
+  )
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "incremental-patch",
+    trace,
+    visualPlan(
+      regions,
+      [
+        { type: "required", regions: ["patch", "following"] },
+        { type: "unique", regions: ["patch", "following"] },
+        { type: "stable", regions: ["patch", "following"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: ["following"], maxPositionReversals: 0 },
+        { type: "label-stability", regions: "all" },
+        { type: "preserve-bottom-anchor" },
+        { type: "flow", regions: ["patch", "following"] },
+      ],
+      { perMarker: true },
+    ),
+  )
+  await expect(trigger).toHaveAttribute("aria-expanded", "true")
+  await expect(page.locator('[data-scope="apply-patch"] [data-type="delete"]')).toBeVisible()
+})
+
+function patchFile(filePath: string, type: "add" | "update" | "delete") {
+  return {
+    filePath,
+    relativePath: filePath,
+    type,
+    additions: type === "delete" ? 0 : 4,
+    deletions: type === "add" ? 0 : 3,
+    before: type === "add" ? undefined : source(false),
+    after: type === "delete" ? undefined : source(true),
+  }
+}
+
+function source(changed: boolean) {
+  return Array.from({ length: 12 }, (_, index) => `export const value${index} = ${changed ? index + 1 : index}\n`).join(
+    "",
+  )
+}

packages/app/e2e/performance/timeline-stability/fixture.test.ts

@@ -0,0 +1,68 @@
+import { describe, expect, test } from "bun:test"
+import {
+  assistantMessage,
+  event,
+  toolPart,
+  userMessage,
+  validateTimelineEvent,
+  validateTimelineMessages,
+  type PartSeed,
+} from "./fixture"
+
+describe("timeline fixture validation", () => {
+  test("accepts a valid timeline", () => {
+    expect(validateTimelineMessages([userMessage(), assistantMessage()])).toHaveLength(2)
+  })
+
+  test("rejects malformed SDK values at runtime", () => {
+    expect(() =>
+      assistantMessage([], {
+        error: { name: "APIError", data: { message: "failed" } } as never,
+      }),
+    ).toThrow()
+    expect(() =>
+      validateTimelineEvent({
+        directory: "C:/OpenCode/TimelineStability",
+        payload: {
+          id: "evt_invalid_status",
+          type: "session.status",
+          properties: { sessionID: "ses_timeline_stability", status: { type: "retry", attempt: 1 } },
+        },
+      }),
+    ).toThrow()
+  })
+
+  test("rejects duplicate IDs and orphan assistants", () => {
+    expect(() => validateTimelineMessages([userMessage(), userMessage()])).toThrow(/duplicate message ID/)
+    expect(() =>
+      validateTimelineMessages([userMessage(), assistantMessage([], { parentID: "msg_missing_parent" })]),
+    ).toThrow(/parent user/)
+  })
+
+  test("assigns deterministic event IDs", () => {
+    const first = event("session.status", { sessionID: "ses_timeline_stability", status: { type: "busy" } })
+    const second = event("session.status", { sessionID: "ses_timeline_stability", status: { type: "idle" } })
+    expect(first.payload.id).toMatch(/^evt_timeline_\d{4}$/)
+    expect(Number(second.payload.id.slice(-4))).toBe(Number(first.payload.id.slice(-4)) + 1)
+  })
+})
+
+if (false) {
+  const userSeed = { id: "prt_type_user", type: "text", text: "typed" } satisfies PartSeed<"user">
+  userMessage([userSeed])
+
+  // @ts-expect-error Tool completion fields are not valid while pending.
+  toolPart("prt_invalid_pending", "bash", "pending", {}, { output: "impossible" })
+  // @ts-expect-error Tool completion fields are not valid while running.
+  toolPart("prt_invalid_running", "bash", "running", {}, { output: "impossible" })
+  // @ts-expect-error Tool error fields are not valid after completion.
+  toolPart("prt_invalid_completed", "bash", "completed", {}, { error: "impossible" })
+
+  assistantMessage([
+    // @ts-expect-error Agent references belong to user messages, not assistant messages.
+    { id: "prt_invalid_owner", type: "agent", name: "explore", source: { value: "@explore", start: 0, end: 8 } },
+  ])
+
+  // @ts-expect-error Retry status events require message and next.
+  event("session.status", { sessionID: "ses_timeline_stability", status: { type: "retry", attempt: 1 } })
+}

packages/app/e2e/performance/timeline-stability/fixture.ts

@@ -0,0 +1,561 @@
+import { base64Encode } from "@opencode-ai/core/util/encode"
+import { Event } from "@opencode-ai/schema/event"
+import { SessionStatusEvent } from "@opencode-ai/schema/session-status-event"
+import { SessionV1 } from "@opencode-ai/schema/session-v1"
+import type {
+  AssistantMessage,
+  GlobalEvent,
+  Message,
+  Part,
+  Session,
+  SessionStatus,
+  ToolPart,
+  ToolState,
+  UserMessage,
+} from "@opencode-ai/sdk/v2/client"
+import { expect, type Page } from "@playwright/test"
+import { Schema } from "effect"
+import { mockOpenCodeServer } from "../../utils/mock-server"
+import { installSseTransport } from "../../utils/sse-transport"
+import { expectSessionTitle } from "../../utils/waits"
+
+export const directory = "C:/OpenCode/TimelineStability"
+export const projectID = "proj_timeline_stability"
+export const sessionID = "ses_timeline_stability"
+export const userID = "msg_1000_timeline_user"
+export const assistantID = "msg_1001_timeline_assistant"
+export const title = "Timeline visual stability"
+export const model = { providerID: "opencode", modelID: "claude-opus-4-6", variant: "max" }
+
+type TimelinePayload = Extract<
+  GlobalEvent["payload"],
+  {
+    type:
+      | "message.updated"
+      | "message.removed"
+      | "message.part.updated"
+      | "message.part.removed"
+      | "message.part.delta"
+      | "session.status"
+  }
+>
+
+type DeepReadonly<Value> = Value extends readonly unknown[]
+  ? { readonly [Key in keyof Value]: DeepReadonly<Value[Key]> }
+  : Value extends object
+    ? { readonly [Key in keyof Value]: DeepReadonly<Value[Key]> }
+    : Value
+
+export type TimelineEvent = DeepReadonly<Omit<GlobalEvent, "payload"> & { payload: TimelinePayload }>
+export type EventPayload = TimelineEvent
+export type ToolStatus = ToolState["status"]
+export type TimelineMessage = { info: UserMessage; parts: Part[] } | { info: AssistantMessage; parts: Part[] }
+
+type UserPart = Extract<Part, { type: "text" | "file" | "agent" | "subtask" }>
+type AssistantPart = Exclude<Part, { type: "agent" | "subtask" }>
+type OwnedPart<Owner extends Message["role"]> = Owner extends "user" ? UserPart : AssistantPart
+export type PartSeed<Owner extends Message["role"]> =
+  OwnedPart<Owner> extends infer Candidate
+    ? Candidate extends Part
+      ? Omit<Candidate, "sessionID" | "messageID">
+      : never
+    : never
+
+type ToolOptions<State extends ToolStatus> = State extends "pending"
+  ? { output?: never; title?: never; metadata?: never; error?: never }
+  : State extends "running"
+    ? { title?: string; metadata?: Record<string, unknown>; output?: never; error?: never }
+    : State extends "error"
+      ? { error?: string; metadata?: Record<string, unknown>; output?: never; title?: never }
+      : { output?: string; title?: string; metadata?: Record<string, unknown>; error?: never }
+
+const decodeOptions = { errors: "all", onExcessProperty: "error" } as const
+const decodeMessage = Schema.decodeUnknownSync(SessionV1.WithParts)
+const decodePart = Schema.decodeUnknownSync(SessionV1.Part)
+const decodeStatus = Schema.decodeUnknownSync(SessionStatusEvent.Info)
+const timelineEventSchema = Schema.Union([
+  eventSchema("message.updated", SessionV1.Event.MessageUpdated.data),
+  eventSchema("message.removed", SessionV1.Event.MessageRemoved.data),
+  eventSchema("message.part.updated", SessionV1.Event.PartUpdated.data),
+  eventSchema("message.part.removed", SessionV1.Event.PartRemoved.data),
+  eventSchema("message.part.delta", SessionV1.Event.PartDelta.data),
+  eventSchema("session.status", SessionStatusEvent.Status.data),
+])
+const decodeEvent = Schema.decodeUnknownSync(timelineEventSchema)
+let eventSequence = 0
+
+export async function setupTimeline(
+  page: Page,
+  input: {
+    messages?: TimelineMessage[]
+    settings?: Record<string, boolean>
+    sessions?: Session[]
+    cpuRate?: number
+    viewport?: { width: number; height: number }
+    eventRetry?: number
+    reducedMotion?: boolean
+    locale?: string
+    deviceScaleFactor?: number
+    seedHistory?: boolean
+  } = {},
+) {
+  const sessions = input.sessions ?? [session()]
+  const messages = validateTimelineMessages([
+    ...(input.seedHistory ? historyMessages(18) : []),
+    ...(input.messages ?? [userMessage(), assistantMessage()]),
+  ])
+  const active = messages.findLast((message) => message.info.role === "assistant")
+  const initialStatus = decodeStatus(
+    active?.info.role === "assistant" && active.info.time.completed === undefined ? { type: "busy" } : { type: "idle" },
+    decodeOptions,
+  )
+  const transport = await installSseTransport<EventPayload>(page, {
+    server: `http://${process.env.PLAYWRIGHT_SERVER_HOST ?? "127.0.0.1"}:${process.env.PLAYWRIGHT_SERVER_PORT ?? "4096"}`,
+    retry: input.eventRetry ?? 20,
+  })
+  await mockOpenCodeServer(page, {
+    directory,
+    project: project(),
+    provider: provider(),
+    sessions,
+    sessionStatus: { [sessionID]: initialStatus },
+    pageMessages: () => ({
+      items: messages,
+    }),
+  })
+  await page.addInitScript((settings) => {
+    localStorage.setItem(
+      "settings.v3",
+      JSON.stringify({
+        general: {
+          editToolPartsExpanded: false,
+          shellToolPartsExpanded: false,
+          showReasoningSummaries: false,
+          showSessionProgressBar: true,
+          ...settings,
+        },
+      }),
+    )
+  }, input.settings ?? {})
+  if (input.locale) {
+    await page.addInitScript((locale) => {
+      localStorage.setItem("opencode.global.dat:language", JSON.stringify({ locale }))
+    }, input.locale)
+  }
+  if (input.reducedMotion) await page.emulateMedia({ reducedMotion: "reduce" })
+  await page.setViewportSize(input.viewport ?? { width: 1400, height: 900 })
+  if (input.deviceScaleFactor) {
+    const devtools = await page.context().newCDPSession(page)
+    const viewport = input.viewport ?? { width: 1400, height: 900 }
+    await devtools.send("Emulation.setDeviceMetricsOverride", {
+      width: viewport.width,
+      height: viewport.height,
+      deviceScaleFactor: input.deviceScaleFactor,
+      mobile: false,
+    })
+  }
+  await page.goto(`/${base64Encode(directory)}/session/${sessionID}`)
+  await transport.waitForConnection()
+  await expectSessionTitle(page, title)
+  if (input.cpuRate && input.cpuRate > 1) {
+    const devtools = await page.context().newCDPSession(page)
+    await devtools.send("Emulation.setCPUThrottlingRate", { rate: input.cpuRate })
+  }
+
+  return {
+    transport,
+    async send(event: TimelineEvent, delay = 0) {
+      const valid = validateTimelineEvent(event)
+      await transport.send(valid, { marker: describeEvent(valid) })
+      if (delay) await page.waitForTimeout(delay)
+    },
+    async sendAll(sequence: { event: TimelineEvent; delay: number }[]) {
+      for (const item of sequence) {
+        const valid = validateTimelineEvent(item.event)
+        await transport.send(valid, { marker: describeEvent(valid) })
+        await page.waitForTimeout(item.delay)
+      }
+    },
+    async settle(frames = 3) {
+      await page.evaluate(
+        (frames) =>
+          new Promise<void>((resolve) => {
+            let remaining = frames
+            const tick = () => {
+              remaining--
+              if (remaining <= 0) return resolve()
+              requestAnimationFrame(tick)
+            }
+            requestAnimationFrame(tick)
+          }),
+        frames,
+      )
+    },
+    async waitForPart(partID: string) {
+      await expect(page.locator(`[data-timeline-part-id="${partID}"]`).first()).toBeVisible()
+    },
+  }
+}
+
+function describeEvent(event: EventPayload) {
+  if (event.payload.type === "message.part.updated") {
+    const part = event.payload.properties.part
+    return [
+      event.payload.type,
+      part.id,
+      part.type === "tool" ? part.tool : part.type,
+      part.type === "tool" ? part.state.status : undefined,
+    ]
+      .filter(Boolean)
+      .join(":")
+  }
+  if (event.payload.type === "session.status") {
+    const status = event.payload.properties.status
+    return [event.payload.type, status.type, status.type === "retry" ? status.attempt : undefined]
+      .filter((value) => value !== undefined)
+      .join(":")
+  }
+  return event.payload.type
+}
+
+export function event<const Type extends TimelinePayload["type"]>(
+  type: Type,
+  properties: Extract<TimelinePayload, { type: Type }>["properties"],
+): TimelineEvent
+export function event(type: TimelinePayload["type"], properties: TimelinePayload["properties"]): TimelineEvent {
+  return validateTimelineEvent({
+    directory,
+    payload: { id: `evt_timeline_${String(++eventSequence).padStart(4, "0")}`, type, properties },
+  })
+}
+
+export function validateTimelineEvent(input: unknown): TimelineEvent {
+  return decodeEvent(input, decodeOptions)
+}
+
+export function validateTimelineMessages(input: readonly TimelineMessage[]): TimelineMessage[] {
+  input.forEach((message) => decodeMessage(message, decodeOptions))
+  const messages = [...input]
+  const messageIDs = new Set<string>()
+  const partIDs = new Set<string>()
+  const users = new Set(messages.filter((message) => message.info.role === "user").map((message) => message.info.id))
+
+  messages.forEach((message) => {
+    if (messageIDs.has(message.info.id))
+      throw new Error(`Timeline fixture has duplicate message ID: ${message.info.id}`)
+    messageIDs.add(message.info.id)
+    if (message.info.role === "assistant" && !users.has(message.info.parentID))
+      throw new Error(`Timeline assistant ${message.info.id} must reference a parent user in the fixture`)
+    message.parts.forEach((part) => {
+      if (part.sessionID !== message.info.sessionID || part.messageID !== message.info.id)
+        throw new Error(`Timeline part ${part.id} ownership does not match message ${message.info.id}`)
+      if (message.info.role === "user" && !["text", "file", "agent", "subtask"].includes(part.type))
+        throw new Error(`Timeline user message ${message.info.id} cannot own ${part.type} part ${part.id}`)
+      if (message.info.role === "assistant" && ["agent", "subtask"].includes(part.type))
+        throw new Error(`Timeline assistant message ${message.info.id} cannot own ${part.type} part ${part.id}`)
+      if (partIDs.has(part.id)) throw new Error(`Timeline fixture has duplicate part ID: ${part.id}`)
+      partIDs.add(part.id)
+    })
+  })
+  return messages
+}
+
+export async function waitForVisualSettle(page: Page, selectors: string[], stableFrames = 3) {
+  await page.waitForFunction(
+    ({ selectors, stableFrames }) => {
+      const elements = selectors.map((selector) => document.querySelector<HTMLElement>(selector))
+      if (elements.some((element) => !element)) return false
+      return new Promise<boolean>((resolve) => {
+        let stable = 0
+        let previous = ""
+        const sample = () => {
+          const signature = JSON.stringify(
+            elements.map((element) => {
+              const rect = element!.getBoundingClientRect()
+              return [Math.round(rect.top * 10), Math.round(rect.bottom * 10), Math.round(rect.height * 10)]
+            }),
+          )
+          stable = signature === previous ? stable + 1 : 0
+          previous = signature
+          const ordered = elements
+            .slice(1)
+            .every(
+              (element, index) =>
+                elements[index]!.getBoundingClientRect().bottom <= element!.getBoundingClientRect().top + 0.5,
+            )
+          if (stable >= stableFrames && ordered) return resolve(true)
+          requestAnimationFrame(sample)
+        }
+        requestAnimationFrame(sample)
+      })
+    },
+    { selectors, stableFrames },
+  )
+}
+
+export function historyMessages(count: number): TimelineMessage[] {
+  return Array.from({ length: count }, (_, index) => {
+    const value = String(index).padStart(4, "0")
+    const historyUserID = `msg_0${value}_history_a_user`
+    return [
+      userMessage(undefined, { id: historyUserID, created: 1690000000000 + index * 10_000 }),
+      assistantMessage(
+        [
+          {
+            id: `prt_0${value}_history_text`,
+            type: "text",
+            text: `Historical response ${index}. ${"Existing session content keeps the virtual timeline realistic. ".repeat(5)}`,
+          },
+        ],
+        {
+          id: `msg_0${value}_history_b_assistant`,
+          parentID: historyUserID,
+          created: 1690000001000 + index * 10_000,
+        },
+      ),
+    ]
+  }).flat()
+}
+
+export function partUpdated(part: Part | PartSeed<"assistant">) {
+  const owned = "messageID" in part ? part : { ...part, sessionID, messageID: assistantID }
+  decodePart(owned, decodeOptions)
+  return event("message.part.updated", {
+    sessionID,
+    part: owned,
+    time: 1700000002000,
+  })
+}
+
+export function partDelta(partID: string, delta: string, messageID = assistantID) {
+  return event("message.part.delta", { sessionID, messageID, partID, field: "text", delta })
+}
+
+export function messageUpdated(info: Message) {
+  return event("message.updated", { sessionID, info })
+}
+
+export function status(type: SessionStatus["type"], attempt = 1) {
+  return event("session.status", {
+    sessionID,
+    status: type === "retry" ? { type, attempt, message: "Rate limited", next: 1700000010000 } : { type },
+  })
+}
+
+export function userMessage(
+  parts?: PartSeed<"user">[],
+  input: { id?: string; summary?: UserMessage["summary"]; created?: number } = {},
+): Extract<TimelineMessage, { info: { role: "user" } }> {
+  const id = input.id ?? userID
+  const seeds = parts ?? [userText("Build the timeline stability matrix.", { id: `prt_${id}_text` })]
+  const message = {
+    info: {
+      id,
+      sessionID,
+      role: "user",
+      time: { created: input.created ?? 1700000000000 },
+      summary: input.summary ?? { diffs: [] },
+      agent: "build",
+      model,
+    },
+    parts: seeds.map((part) => ({
+      ...part,
+      sessionID,
+      messageID: id,
+    })),
+  } satisfies Extract<TimelineMessage, { info: { role: "user" } }>
+  decodeMessage(message, decodeOptions)
+  return message
+}
+
+export function assistantMessage(
+  parts: PartSeed<"assistant">[] = [],
+  input: {
+    id?: string
+    parentID?: string
+    completed?: boolean
+    error?: AssistantMessage["error"]
+    created?: number
+  } = {},
+): Extract<TimelineMessage, { info: { role: "assistant" } }> {
+  const id = input.id ?? assistantID
+  const message = {
+    info: {
+      id,
+      sessionID,
+      role: "assistant",
+      time: {
+        created: input.created ?? 1700000001000,
+        ...(input.completed === false ? {} : { completed: (input.created ?? 1700000001000) + 1_000 }),
+      },
+      parentID: input.parentID ?? userID,
+      modelID: model.modelID,
+      providerID: model.providerID,
+      mode: "build",
+      agent: "build",
+      path: { cwd: directory, root: directory },
+      cost: 0.01,
+      tokens: { input: 100, output: 200, reasoning: 0, cache: { read: 0, write: 0 } },
+      variant: "max",
+      ...(input.error ? { error: input.error } : {}),
+    },
+    parts: parts.map((part) => ({ ...part, sessionID, messageID: id })),
+  } satisfies Extract<TimelineMessage, { info: { role: "assistant" } }>
+  decodeMessage(message, decodeOptions)
+  return message
+}
+
+export function userText(
+  text: string,
+  input: Partial<Omit<Extract<PartSeed<"user">, { type: "text" }>, "type" | "text">> = {},
+): Extract<PartSeed<"user">, { type: "text" }> {
+  return { id: "prt_user_text", type: "text", text, ...input }
+}
+
+export function textPart(id: string, text: string): Extract<PartSeed<"assistant">, { type: "text" }> {
+  return { id, type: "text", text }
+}
+
+export function reasoningPart(id: string, text: string): Extract<PartSeed<"assistant">, { type: "reasoning" }> {
+  return { id, type: "reasoning", text, time: { start: 1700000001000 } }
+}
+
+export function toolPart(
+  id: string,
+  tool: string,
+  state: "pending",
+  input: Record<string, unknown>,
+  options?: ToolOptions<"pending">,
+): Omit<ToolPart, "sessionID" | "messageID">
+export function toolPart(
+  id: string,
+  tool: string,
+  state: "running",
+  input: Record<string, unknown>,
+  options?: ToolOptions<"running">,
+): Omit<ToolPart, "sessionID" | "messageID">
+export function toolPart(
+  id: string,
+  tool: string,
+  state: "completed",
+  input: Record<string, unknown>,
+  options?: ToolOptions<"completed">,
+): Omit<ToolPart, "sessionID" | "messageID">
+export function toolPart(
+  id: string,
+  tool: string,
+  state: "error",
+  input: Record<string, unknown>,
+  options?: ToolOptions<"error">,
+): Omit<ToolPart, "sessionID" | "messageID">
+export function toolPart(
+  id: string,
+  tool: string,
+  state: ToolStatus,
+  input: Record<string, unknown>,
+  options: ToolOptions<ToolStatus> = {},
+): Omit<ToolPart, "sessionID" | "messageID"> {
+  const base = { id, type: "tool" as const, callID: `call_${id}`, tool }
+  if (state === "pending") return { ...base, state: { status: state, input, raw: "" } }
+  if (state === "running")
+    return {
+      ...base,
+      state: {
+        status: state,
+        input,
+        title: options.title,
+        metadata: options.metadata ?? {},
+        time: { start: 1700000001000 },
+      },
+    }
+  if (state === "error")
+    return {
+      ...base,
+      state: {
+        status: state,
+        input,
+        error: options.error ?? "Tool failed",
+        metadata: options.metadata ?? {},
+        time: { start: 1700000001000, end: 1700000002000 },
+      },
+    }
+  return {
+    ...base,
+    state: {
+      status: state,
+      input,
+      output: options.output ?? "Completed",
+      title: options.title ?? tool,
+      metadata: options.metadata ?? {},
+      time: { start: 1700000001000, end: 1700000002000 },
+    },
+  }
+}
+
+export function shell(
+  id: string,
+  state: ToolStatus,
+  output = "",
+  command = `echo ${id}`,
+): Omit<ToolPart, "sessionID" | "messageID"> {
+  if (state === "pending") return toolPart(id, "bash", state, { command })
+  if (state === "running")
+    return toolPart(id, "bash", state, { command }, { title: command, metadata: { command, output } })
+  if (state === "error")
+    return toolPart(id, "bash", state, { command }, { error: output || undefined, metadata: { command, output } })
+  return toolPart(id, "bash", state, { command }, { title: command, output, metadata: { command, output } })
+}
+
+export function completedAssistantInfo(info: AssistantMessage): AssistantMessage {
+  return { ...info, time: { ...info.time, completed: 1700000003000 } }
+}
+
+export function project() {
+  return {
+    id: projectID,
+    worktree: directory,
+    vcs: "git",
+    name: "timeline-stability",
+    time: { created: 1700000000000, updated: 1700000000000 },
+    sandboxes: [],
+  }
+}
+
+export function session(input: Partial<Session> = {}): Session {
+  return {
+    id: sessionID,
+    slug: "timeline-stability",
+    projectID,
+    directory,
+    title,
+    version: "dev",
+    time: { created: 1700000000000, updated: 1700000000000 },
+    ...input,
+  }
+}
+
+function eventSchema<
+  const Type extends TimelinePayload["type"],
+  const Properties extends Schema.Codec<unknown, unknown>,
+>(type: Type, properties: Properties) {
+  return Schema.Struct({
+    directory: Schema.String,
+    project: Schema.optional(Schema.String),
+    workspace: Schema.optional(Schema.String),
+    payload: Schema.Struct({ id: Event.ID, type: Schema.Literal(type), properties }),
+  })
+}
+
+function provider() {
+  return {
+    all: [
+      {
+        id: "opencode",
+        name: "OpenCode",
+        models: { "claude-opus-4-6": { id: "claude-opus-4-6", name: "Claude Opus 4.6", limit: { context: 200_000 } } },
+      },
+    ],
+    connected: ["opencode"],
+    default: { providerID: "opencode", modelID: "claude-opus-4-6" },
+  }
+}

packages/app/e2e/performance/timeline-stability/interaction.spec.ts

@@ -0,0 +1,242 @@
+import { expect, test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import { assistantMessage, setupTimeline, shell, textPart, toolPart, userMessage, waitForVisualSettle } from "./fixture"
+
+test("expands and collapses a long completed shell without overlap", async ({ page }, testInfo) => {
+  const shellID = "prt_interaction_01_shell"
+  const followingID = "prt_interaction_02_following"
+  await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([shell(shellID, "completed", lines(50)), textPart(followingID, "Following shell expansion")]),
+    ],
+    settings: { shellToolPartsExpanded: false },
+    cpuRate: 4,
+    seedHistory: true,
+  })
+  const trigger = page.locator(`[data-timeline-part-id="${shellID}"] [data-slot="collapsible-trigger"]`)
+  await waitForVisualSettle(page, [`[data-timeline-part-id="${shellID}"]`, `[data-timeline-part-id="${followingID}"]`])
+  const regions = defineVisualRegions({
+    shell: { selector: `[data-timeline-part-id="${shellID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  const plan = visualPlan(regions, [
+    { type: "required", regions: ["shell", "following"] },
+    { type: "unique", regions: ["shell", "following"] },
+    { type: "stable", regions: ["shell", "following"] },
+    { type: "opacity", regions: "all" },
+    { type: "continuity", regions: "all" },
+    { type: "motion", regions: "all", maxPositionReversals: 0 },
+    { type: "label-stability", regions: "all" },
+    { type: "preserve-bottom-anchor" },
+    { type: "flow", regions: ["shell", "following"] },
+  ])
+  await startVisualProbe(page, regions)
+  await trigger.click()
+  await expect(trigger).toHaveAttribute("aria-expanded", "true")
+  await page.waitForTimeout(500)
+  const expanded = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(testInfo, "shell-expand", expanded, plan)
+
+  await startVisualProbe(page, regions)
+  await trigger.click()
+  await expect(trigger).toHaveAttribute("aria-expanded", "false")
+  await page.waitForTimeout(500)
+  const collapsed = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(testInfo, "shell-collapse", collapsed, plan)
+})
+
+test("expands and collapses a completed context group without overlap", async ({ page }, testInfo) => {
+  const ids = [
+    "prt_interaction_01_read",
+    "prt_interaction_02_glob",
+    "prt_interaction_03_grep",
+    "prt_interaction_04_list",
+  ]
+  const group = `[data-timeline-part-ids="${ids.join(",")}"]`
+  const followingID = "prt_interaction_context_following"
+  await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([
+        toolPart(ids[0]!, "read", "completed", { filePath: "src/a.ts" }),
+        toolPart(ids[1]!, "glob", "completed", { path: ".", pattern: "**/*.ts" }),
+        toolPart(ids[2]!, "grep", "completed", { path: ".", pattern: "stable" }),
+        toolPart(ids[3]!, "list", "completed", { path: "src" }),
+        textPart(followingID, "Following context expansion"),
+      ]),
+    ],
+    cpuRate: 4,
+    seedHistory: true,
+  })
+  const trigger = page.locator(`${group} [data-slot="collapsible-trigger"]`)
+  await waitForVisualSettle(page, [group, `[data-timeline-part-id="${followingID}"]`])
+  for (const [name, expanded] of [
+    ["context-expand", true],
+    ["context-collapse", false],
+    ["context-reexpand", true],
+  ] as const) {
+    const regions = defineVisualRegions({
+      context: { selector: group, closest: '[data-timeline-row="AssistantPart"]' },
+      following: {
+        selector: `[data-timeline-part-id="${followingID}"]`,
+        closest: '[data-timeline-row="AssistantPart"]',
+      },
+    })
+    await startVisualProbe(page, regions)
+    await trigger.click()
+    await expect(trigger).toHaveAttribute("aria-expanded", String(expanded))
+    await page.waitForTimeout(500)
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    await reportVisualStability(
+      testInfo,
+      name,
+      trace,
+      visualPlan(regions, [
+        { type: "required", regions: ["context", "following"] },
+        { type: "unique", regions: ["context", "following"] },
+        { type: "stable", regions: ["context", "following"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all", maxPositionReversals: 0 },
+        { type: "label-stability", regions: "all" },
+        { type: "preserve-bottom-anchor" },
+        { type: "flow", regions: ["context", "following"] },
+      ]),
+    )
+  }
+})
+
+test("expands and collapses an edit diff without moving twice", async ({ page }, testInfo) => {
+  const editID = "prt_interaction_edit"
+  const followingID = "prt_interaction_edit_following"
+  await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([
+        toolPart(
+          editID,
+          "edit",
+          "completed",
+          { filePath: "src/edit.ts" },
+          {
+            metadata: {
+              filediff: {
+                file: "src/edit.ts",
+                additions: 40,
+                deletions: 40,
+                before: source(40, false),
+                after: source(40, true),
+              },
+            },
+          },
+        ),
+        textPart(followingID, "Following edit expansion"),
+      ]),
+    ],
+    settings: { editToolPartsExpanded: false },
+    cpuRate: 4,
+    seedHistory: true,
+  })
+  const trigger = page.locator(`[data-timeline-part-id="${editID}"] [data-slot="collapsible-trigger"]`).first()
+  await waitForVisualSettle(page, [`[data-timeline-part-id="${editID}"]`, `[data-timeline-part-id="${followingID}"]`])
+  const regions = defineVisualRegions({
+    edit: { selector: `[data-timeline-part-id="${editID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await trigger.click()
+  await expect(trigger).toHaveAttribute("aria-expanded", "true")
+  await page.waitForTimeout(900)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "edit-expand",
+    trace,
+    visualPlan(regions, [
+      { type: "required", regions: ["edit", "following"] },
+      { type: "unique", regions: ["edit", "following"] },
+      { type: "stable", regions: ["edit", "following"] },
+      { type: "opacity", regions: "all" },
+      { type: "continuity", regions: "all" },
+      { type: "motion", regions: "all", maxPositionReversals: 0, maxReversals: 1 },
+      { type: "label-stability", regions: "all" },
+      { type: "preserve-bottom-anchor" },
+      { type: "flow", regions: ["edit", "following"] },
+    ]),
+  )
+})
+
+test("shows all and expands historical diff summary without overlap", async ({ page }, testInfo) => {
+  const firstUser = userMessage(undefined, {
+    summary: {
+      diffs: Array.from({ length: 12 }, (_, index) => ({
+        file: `src/diff-${index}.ts`,
+        additions: 1,
+        deletions: 1,
+        patch: `@@ -1 +1 @@\n-export const value = ${index}\n+export const value = ${index + 1}`,
+      })),
+    },
+  })
+  const nextUserID = "msg_2000_diff_interaction_user"
+  await setupTimeline(page, {
+    messages: [
+      firstUser,
+      assistantMessage(),
+      userMessage(undefined, { id: nextUserID, created: 1700000010000 }),
+      assistantMessage([], {
+        id: "msg_2001_diff_interaction_assistant",
+        parentID: nextUserID,
+        created: 1700000011000,
+      }),
+    ],
+    cpuRate: 4,
+  })
+  const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
+  await scroller.evaluate((element) => (element.scrollTop = 0))
+  const diff = page.locator('[data-timeline-row="DiffSummary"]')
+  const following = page.locator(`[data-message-id="${nextUserID}"]`).first()
+  await expect(diff).toBeVisible()
+  const regions = defineVisualRegions({
+    diff: { selector: '[data-timeline-row="DiffSummary"]' },
+    following: { selector: `[data-message-id="${nextUserID}"]` },
+  })
+  await startVisualProbe(page, regions)
+  await page.getByText(/show all/i).click()
+  await page.waitForTimeout(500)
+  await diff.locator('[data-slot="session-turn-diff-trigger"]').first().click()
+  await page.waitForTimeout(900)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "diff-summary-expand",
+    trace,
+    visualPlan(regions, [
+      { type: "required", regions: ["diff", "following"] },
+      { type: "unique", regions: ["diff", "following"] },
+      { type: "stable", regions: ["diff", "following"] },
+      { type: "opacity", regions: "all" },
+      { type: "continuity", regions: "all" },
+      { type: "motion", regions: "all", maxPositionReversals: 1, maxReversals: 2 },
+      { type: "label-stability", regions: "all" },
+      { type: "flow", regions: ["diff", "following"] },
+    ]),
+  )
+})
+
+function lines(count: number) {
+  return Array.from({ length: count }, (_, index) => `line ${index + 1}`).join("\n")
+}
+
+function source(count: number, changed: boolean) {
+  return Array.from(
+    { length: count },
+    (_, index) => `export const value${index} = ${changed ? index + 1 : index}\n`,
+  ).join("")
+}

packages/app/e2e/performance/timeline-stability/lifecycle.spec.ts

@@ -0,0 +1,157 @@
+import { expect, test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  mapVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import {
+  assistantMessage,
+  completedAssistantInfo,
+  messageUpdated,
+  partDelta,
+  partUpdated,
+  reasoningPart,
+  setupTimeline,
+  shell,
+  status,
+  textPart,
+  userMessage,
+  waitForVisualSettle,
+} from "./fixture"
+
+test.describe("timeline visual lifecycle stability", () => {
+  test("streams empty, short, and long parallel shells to staggered completion", async ({ page }, testInfo) => {
+    test.setTimeout(180_000)
+    const ids = ["prt_parallel_01_empty", "prt_parallel_02_short", "prt_parallel_03_long"] as const
+    const initial = ids.map((id) => shell(id, "running"))
+    const followingID = "prt_parallel_04_following"
+    const assistant = assistantMessage([...initial, textPart(followingID, "Following all parallel shells.")], {
+      completed: false,
+    })
+    const timeline = await setupTimeline(page, {
+      messages: [userMessage(), assistant],
+      settings: { shellToolPartsExpanded: true, showReasoningSummaries: true },
+      cpuRate: 4,
+      eventRetry: 24,
+      seedHistory: true,
+    })
+    await timeline.send(status("busy"), 150)
+    for (const id of ids) await timeline.waitForPart(id)
+    const scroller = page.locator(".scroll-view__viewport", {
+      has: page.locator('[data-timeline-row="AssistantPart"]'),
+    })
+    await scroller.evaluate((element) => (element.scrollTop = element.scrollHeight))
+    const regions = defineVisualRegions({
+      prt_shell_empty: shellRegion(ids[0]),
+      prt_shell_short: shellRegion(ids[1]),
+      prt_shell_long: shellRegion(ids[2]),
+      following: shellRegion(followingID),
+    })
+    await waitForVisualSettle(page, [`[data-timeline-part-id="${followingID}"]`])
+    await startVisualProbe(page, regions)
+    await timeline.sendAll([
+      { event: partUpdated(shell(ids[0]!, "completed", "")), delay: 180 },
+      { event: partUpdated(shell(ids[2]!, "running", lines(10))), delay: 70 },
+      { event: partUpdated(shell(ids[1]!, "running", lines(2))), delay: 110 },
+      { event: partUpdated(shell(ids[2]!, "running", lines(25))), delay: 80 },
+      { event: partUpdated(shell(ids[1]!, "completed", lines(2))), delay: 260 },
+      { event: partUpdated(shell(ids[2]!, "running", lines(50))), delay: 100 },
+      { event: partUpdated(shell(ids[2]!, "completed", lines(50))), delay: 450 },
+      { event: messageUpdated(completedAssistantInfo(assistant.info)), delay: 100 },
+      { event: status("idle"), delay: 700 },
+    ])
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    await reportVisualStability(
+      testInfo,
+      "parallel-shells",
+      trace,
+      visualPlan(
+        regions,
+        [
+          { type: "required", regions: ["prt_shell_empty", "prt_shell_short", "prt_shell_long", "following"] },
+          { type: "unique", regions: ["prt_shell_empty", "prt_shell_short", "prt_shell_long"] },
+          { type: "stable", regions: ["prt_shell_empty", "prt_shell_short", "prt_shell_long", "following"] },
+          { type: "opacity", regions: "all" },
+          { type: "continuity", regions: "all" },
+          { type: "motion", regions: "all", maxPositionReversals: 0, maxReversals: 4 },
+          { type: "label-stability", regions: "all" },
+          { type: "preserve-bottom-anchor" },
+          { type: "flow", regions: ["prt_shell_empty", "prt_shell_short", "prt_shell_long", "following"] },
+        ],
+        { perMarker: true },
+      ),
+    )
+    await expect(page.locator(`[data-timeline-part-id="${ids[2]}"] [data-slot="bash-pre"]`)).toContainText("line 50")
+
+    const short = page.locator(`[data-timeline-part-id="${ids[1]}"]`)
+    await short.locator('[data-slot="collapsible-trigger"]').click()
+    await expect(short.locator('[data-slot="collapsible-trigger"]')).toHaveAttribute("aria-expanded", "false")
+    await timeline.send(partUpdated(textPart("prt_late_sibling", "A later sibling rerender.")), 250)
+    await expect(short.locator('[data-slot="collapsible-trigger"]')).toHaveAttribute("aria-expanded", "false")
+  })
+
+  test("replaces thinking with streamed reasoning and text without a blank visible turn", async ({
+    page,
+  }, testInfo) => {
+    const reasoningID = "prt_reasoning_visible"
+    const textID = "prt_streamed_text"
+    const assistant = assistantMessage([], { completed: false })
+    const timeline = await setupTimeline(page, {
+      messages: [userMessage(), assistant],
+      settings: { showReasoningSummaries: true },
+      cpuRate: 4,
+    })
+    await timeline.send(status("busy"), 120)
+    await expect(page.locator('[data-timeline-row="Thinking"]')).toBeVisible()
+
+    const regions = defineVisualRegions({
+      thinking: { selector: '[data-timeline-row="Thinking"]' },
+      reasoning: {
+        selector: `[data-timeline-part-id="${reasoningID}"]`,
+        closest: '[data-timeline-row="AssistantPart"]',
+      },
+      text: { selector: `[data-timeline-part-id="${textID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    })
+    await startVisualProbe(page, regions)
+    await timeline.send(partUpdated(reasoningPart(reasoningID, "")), 100)
+    await expect(page.locator(`[data-timeline-part-id="${reasoningID}"]`)).toHaveCount(0)
+    await timeline.send(partUpdated(reasoningPart(reasoningID, "## Planning\n\nChecking the visible timeline.")), 160)
+    await timeline.waitForPart(reasoningID)
+    await expect(page.locator('[data-timeline-row="Thinking"]')).toHaveCount(0)
+    await timeline.send(partUpdated(textPart(textID, "Starting")), 100)
+    await timeline.send(partDelta(textID, " **stable"), 90)
+    await timeline.send(partDelta(textID, " output** with `code` and [a link"), 130)
+    await timeline.send(partDelta(textID, "](https://example.com)."), 220)
+    await timeline.send(messageUpdated(completedAssistantInfo(assistant.info)), 120)
+    await timeline.send(status("idle"), 500)
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    await reportVisualStability(
+      testInfo,
+      "reasoning-text-handoff",
+      trace,
+      visualPlan(regions, [
+        { type: "required", regions: ["reasoning", "text"] },
+        { type: "continuous-any", regions: ["thinking", "reasoning", "text"] },
+        { type: "unique", regions: ["reasoning", "text"] },
+        { type: "stable", regions: ["reasoning", "text"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all", maxReversals: 4 },
+        { type: "label-stability", regions: "all" },
+        { type: "flow", regions: ["reasoning", "text"] },
+      ]),
+    )
+    await expect(page.locator(`[data-timeline-part-id="${textID}"]`)).toContainText("stable output")
+  })
+})
+
+function lines(count: number) {
+  return Array.from({ length: count }, (_, index) => `line ${index + 1}`).join("\n")
+}
+
+function shellRegion(id: string) {
+  return { selector: `[data-timeline-part-id="${id}"]`, closest: '[data-timeline-row="AssistantPart"]' }
+}

packages/app/e2e/performance/timeline-stability/oracle-browser.spec.ts

@@ -0,0 +1,75 @@
+import { expect, test } from "@playwright/test"
+import {
+  analyzeVisualObservations,
+  defineVisualRegions,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import { assistantMessage, setupTimeline, textPart, userMessage } from "./fixture"
+
+test("detects blanking caused by ancestor opacity", async ({ page }) => {
+  const partID = "prt_oracle_ancestor_opacity"
+  await setupTimeline(page, { messages: [userMessage(), assistantMessage([textPart(partID, "Visible content")])] })
+  const row = page.locator(`[data-timeline-part-id="${partID}"]`).first()
+  const regions = defineVisualRegions({
+    content: { selector: `[data-timeline-part-id="${partID}"]` },
+  })
+  await startVisualProbe(page, regions)
+  await row.evaluate((element) => {
+    element.parentElement!.style.opacity = "0"
+  })
+  await page.waitForTimeout(50)
+  await row.evaluate((element) => {
+    element.parentElement!.style.opacity = "1"
+  })
+  await page.waitForTimeout(50)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  const issues = analyzeVisualObservations(
+    trace.samples,
+    visualPlan(regions, [
+      { type: "opacity", regions: "all" },
+      { type: "continuity", regions: "all" },
+      { type: "motion", regions: "all" },
+      { type: "label-stability", regions: "all" },
+    ]),
+  )
+
+  expect(issues.some((issue) => issue.includes("blanked between visible frames"))).toBe(true)
+})
+
+test("detects root opacity when probing descendant opacity", async ({ page }) => {
+  const partID = "prt_oracle_descendant_opacity"
+  await setupTimeline(page, { messages: [userMessage(), assistantMessage([textPart(partID, "Visible content")])] })
+  const row = page.locator(`[data-timeline-part-id="${partID}"]`).first()
+  await row.evaluate((element) => {
+    element.innerHTML = '<span data-probe-opacity="true">Visible content</span>'
+  })
+  const regions = defineVisualRegions({
+    content: {
+      selector: `[data-timeline-part-id="${partID}"]`,
+      opacitySelectors: ['[data-probe-opacity="true"]'],
+    },
+  })
+  await startVisualProbe(page, regions)
+  await row.evaluate((element) => {
+    ;(element as HTMLElement).style.opacity = "0"
+  })
+  await page.waitForTimeout(50)
+  await row.evaluate((element) => {
+    ;(element as HTMLElement).style.opacity = "1"
+  })
+  await page.waitForTimeout(50)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  const issues = analyzeVisualObservations(
+    trace.samples,
+    visualPlan(regions, [
+      { type: "opacity", regions: "all" },
+      { type: "continuity", regions: "all" },
+      { type: "motion", regions: "all" },
+      { type: "label-stability", regions: "all" },
+    ]),
+  )
+
+  expect(issues.some((issue) => issue.includes("blanked between visible frames"))).toBe(true)
+})

packages/app/e2e/performance/timeline-stability/playwright.config.ts

@@ -0,0 +1,17 @@
+import config from "../playwright.config"
+
+export default {
+  ...config,
+  testDir: ".",
+  testMatch: "**/*.spec.ts",
+  outputDir: "../../test-results/timeline-stability",
+  reporter: [["html", { outputFolder: "../../playwright-report/timeline-stability", open: "never" }], ["line"]],
+  retries: 0,
+  workers: 1,
+  use: {
+    ...config.use,
+    trace: "retain-on-failure",
+    screenshot: "only-on-failure",
+    video: "retain-on-failure",
+  },
+}

packages/app/e2e/performance/timeline-stability/scroll-interaction.spec.ts

@@ -0,0 +1,319 @@
+import { expect, test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import {
+  assistantMessage,
+  partUpdated,
+  setupTimeline,
+  shell,
+  textPart,
+  userMessage,
+  type TimelineMessage,
+} from "./fixture"
+
+test("does not reverse visible rows when the user wheels during shell remeasurement", async ({ page }, testInfo) => {
+  const shellID = "prt_wheel_01_shell"
+  const followingID = "prt_wheel_02_following"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      ...history(12),
+      userMessage(),
+      assistantMessage([shell(shellID, "running"), textPart(followingID, "Following wheel interaction")], {
+        completed: false,
+      }),
+    ],
+    settings: { shellToolPartsExpanded: true },
+    cpuRate: 4,
+    reducedMotion: true,
+    seedHistory: true,
+  })
+  const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
+  const regions = defineVisualRegions({
+    shell: { selector: `[data-timeline-part-id="${shellID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(partUpdated(shell(shellID, "running", lines(30))), 80)
+  await scroller.evaluate((element) =>
+    element.dispatchEvent(new WheelEvent("wheel", { bubbles: true, cancelable: true, deltaY: -180 })),
+  )
+  await scroller.evaluate((element) => (element.scrollTop -= 180))
+  await timeline.send(partUpdated(shell(shellID, "running", lines(50))), 250)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(testInfo, "wheel-during-resize", trace, rowPairPlan(regions, 1))
+})
+
+test("does not pull a keyboard-scrolled user during shell remeasurement", async ({ page }, testInfo) => {
+  const shellID = "prt_keyboard_01_shell"
+  const followingID = "prt_keyboard_02_following"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      ...history(12),
+      userMessage(),
+      assistantMessage([shell(shellID, "running"), textPart(followingID, "Following keyboard interaction")], {
+        completed: false,
+      }),
+    ],
+    settings: { shellToolPartsExpanded: true },
+    cpuRate: 4,
+  })
+  const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
+  await scroller.focus()
+  for (let index = 0; index < 3; index++) {
+    await scroller.press("PageUp")
+    await page.waitForTimeout(250)
+  }
+  await expect
+    .poll(() => scroller.evaluate((element) => element.scrollHeight - element.clientHeight - element.scrollTop), {
+      timeout: 20_000,
+    })
+    .toBeGreaterThan(80)
+  await page.waitForFunction(() => {
+    const root = [...document.querySelectorAll<HTMLElement>(".scroll-view__viewport")].find((element) =>
+      element.querySelector("[data-timeline-row]"),
+    )
+    if (!root) return false
+    return new Promise<boolean>((resolve) => {
+      const top = root.scrollTop
+      requestAnimationFrame(() => requestAnimationFrame(() => resolve(Math.abs(root.scrollTop - top) <= 0.5)))
+    })
+  })
+  const anchor = await scroller.evaluate((element) => {
+    const view = element.getBoundingClientRect()
+    return [...element.querySelectorAll<HTMLElement>("[data-timeline-key]")].find((row) => {
+      const rect = row.getBoundingClientRect()
+      return rect.top >= view.top + 40 && rect.bottom <= view.bottom - 40
+    })?.dataset.timelineKey
+  })
+  expect(anchor).toBeTruthy()
+  const regions = defineVisualRegions({
+    anchor: { selector: `[data-timeline-key="${anchor}"]` },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(partUpdated(shell(shellID, "running", lines(50))), 400)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(testInfo, "keyboard-during-resize", trace, anchorPlan(regions))
+})
+
+test("tracks keyboard scrolling from a focused timeline descendant", async ({ page }, testInfo) => {
+  const shellID = "prt_descendant_keyboard_01_shell"
+  const timeline = await setupTimeline(page, {
+    messages: [...history(12), userMessage(), assistantMessage([shell(shellID, "completed", lines(5))])],
+    settings: { shellToolPartsExpanded: false },
+    cpuRate: 4,
+    reducedMotion: true,
+  })
+  const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
+  const row = page.locator(`[data-timeline-part-id="${shellID}"]`).first()
+  const trigger = page.locator(`[data-timeline-part-id="${shellID}"] [data-slot="collapsible-trigger"]`)
+  await row.evaluate((element) => element.setAttribute("tabindex", "0"))
+  await row.focus()
+  for (let index = 0; index < 3; index++) {
+    await row.press("PageUp")
+    await page.waitForTimeout(250)
+  }
+  await expect
+    .poll(() => scroller.evaluate((element) => element.scrollHeight - element.clientHeight - element.scrollTop))
+    .toBeGreaterThan(5)
+  const anchor = await scroller.evaluate((element) => {
+    const view = element.getBoundingClientRect()
+    return [...element.querySelectorAll<HTMLElement>("[data-timeline-key]")].find((row) => {
+      const rect = row.getBoundingClientRect()
+      return rect.top >= view.top + 40 && rect.bottom <= view.bottom - 40
+    })?.dataset.timelineKey
+  })
+  expect(anchor).toBeTruthy()
+  const regions = defineVisualRegions({
+    anchor: { selector: `[data-timeline-key="${anchor}"]` },
+  })
+  await startVisualProbe(page, regions)
+  await trigger.click()
+  await page.waitForTimeout(300)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(testInfo, "descendant-keyboard-resize", trace, anchorPlan(regions))
+})
+
+test("does not claim keyboard scrolling owned by a nested scrollable", async ({ page }) => {
+  const shellID = "prt_nested_keyboard_shell"
+  await setupTimeline(page, {
+    messages: [userMessage(), assistantMessage([shell(shellID, "completed", lines(50))])],
+    settings: { shellToolPartsExpanded: true },
+    cpuRate: 4,
+    reducedMotion: true,
+    seedHistory: true,
+  })
+  const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
+  const nested = page.locator(`[data-timeline-part-id="${shellID}"] [data-scrollable]`)
+  await nested.evaluate((element) => (element.scrollTop = element.scrollHeight))
+  await nested.focus()
+  await page.waitForFunction(() => {
+    const root = [...document.querySelectorAll<HTMLElement>(".scroll-view__viewport")].find((element) =>
+      element.querySelector("[data-timeline-row]"),
+    )
+    if (!root) return false
+    return new Promise<boolean>((resolve) => {
+      const top = root.scrollTop
+      requestAnimationFrame(() => requestAnimationFrame(() => resolve(Math.abs(root.scrollTop - top) <= 0.5)))
+    })
+  })
+  const before = await scroller.evaluate((element) => element.scrollTop)
+  const nestedBefore = await nested.evaluate((element) => element.scrollTop)
+  await nested.press("PageUp")
+  await page.waitForTimeout(300)
+  expect(await scroller.evaluate((element) => element.scrollTop)).toBe(before)
+  expect(await nested.evaluate((element) => element.scrollTop)).toBeLessThan(nestedBefore)
+
+  await nested.evaluate((element) => (element.scrollTop = 0))
+  await scroller.evaluate((element) => (element.scrollTop = Math.min(300, element.scrollHeight - element.clientHeight)))
+  const boundaryBefore = await scroller.evaluate((element) => element.scrollTop)
+  expect(boundaryBefore).toBeGreaterThan(0)
+  await nested.press("PageUp")
+  await expect.poll(() => scroller.evaluate((element) => element.scrollTop)).toBeLessThan(boundaryBefore)
+
+  const nonOverflowing = page.locator(`[data-timeline-part-id="${shellID}"]`).first()
+  await nonOverflowing.evaluate((element) => {
+    element.setAttribute("data-scrollable", "")
+    element.setAttribute("tabindex", "0")
+  })
+  await nonOverflowing.focus()
+  const nonOverflowBefore = await scroller.evaluate((element) => element.scrollTop)
+  await nonOverflowing.press("PageUp")
+  await expect.poll(() => scroller.evaluate((element) => element.scrollTop)).toBeLessThan(nonOverflowBefore)
+})
+
+test("jump to latest lands on stable final rows after offscreen growth", async ({ page }, testInfo) => {
+  const shellID = "prt_jump_01_shell"
+  const followingID = "prt_jump_02_following"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      ...history(20),
+      userMessage(),
+      assistantMessage([shell(shellID, "running"), textPart(followingID, "Latest visible row")], { completed: false }),
+    ],
+    settings: { shellToolPartsExpanded: true },
+    cpuRate: 4,
+  })
+  const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
+  await scroller.evaluate(
+    (element) => (element.scrollTop = Math.max(0, element.scrollHeight - element.clientHeight - 600)),
+  )
+  await timeline.send(partUpdated(shell(shellID, "running", lines(50))), 300)
+  const regions = defineVisualRegions({
+    shell: { selector: `[data-timeline-part-id="${shellID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await page.getByRole("button", { name: /Jump to latest/i }).click()
+  await expect(page.locator(`[data-timeline-part-id="${followingID}"]`)).toBeVisible()
+  await page.waitForTimeout(600)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "jump-latest",
+    trace,
+    visualPlan(regions, [
+      { type: "required", regions: ["shell", "following"] },
+      { type: "unique", regions: ["shell", "following"] },
+      { type: "opacity", regions: "all" },
+      { type: "continuity", regions: "all" },
+      { type: "motion", regions: "all", maxPositionReversals: 1 },
+      { type: "label-stability", regions: "all" },
+      { type: "acquire-bottom-anchor" },
+      { type: "flow", regions: ["shell", "following"] },
+    ]),
+  )
+})
+
+test("handles a single row taller than the viewport", async ({ page }, testInfo) => {
+  const shellID = "prt_tall_01_shell"
+  const followingID = "prt_tall_02_following"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([shell(shellID, "running"), textPart(followingID, "After tall row")], { completed: false }),
+    ],
+    settings: { shellToolPartsExpanded: true },
+    viewport: { width: 900, height: 360 },
+    cpuRate: 4,
+    seedHistory: true,
+  })
+  const regions = defineVisualRegions({
+    shell: { selector: `[data-timeline-part-id="${shellID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(partUpdated(shell(shellID, "completed", lines(100))), 700)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "taller-than-viewport",
+    trace,
+    visualPlan(regions, [
+      { type: "required", regions: ["shell", "following"] },
+      { type: "unique", regions: ["shell", "following"] },
+      { type: "stable", regions: ["shell", "following"] },
+      { type: "opacity", regions: "all" },
+      { type: "continuity", regions: "all" },
+      { type: "motion", regions: "all", maxPositionReversals: 0 },
+      { type: "label-stability", regions: "all" },
+      { type: "preserve-bottom-anchor" },
+      { type: "flow", regions: ["shell", "following"] },
+    ]),
+  )
+})
+
+function history(count: number): TimelineMessage[] {
+  return Array.from({ length: count }, (_, index) => {
+    const prefix = `msg_${String(index).padStart(4, "0")}_scroll`
+    const userID = `${prefix}_a_user`
+    return [
+      userMessage(undefined, { id: userID, created: 1690000000000 + index * 10_000 }),
+      assistantMessage(
+        [textPart(`prt_${String(index).padStart(4, "0")}_scroll`, `History ${index}. ${"content ".repeat(30)}`)],
+        {
+          id: `${prefix}_b_assistant`,
+          parentID: userID,
+          created: 1690000001000 + index * 10_000,
+        },
+      ),
+    ]
+  }).flat()
+}
+
+function lines(count: number) {
+  return Array.from({ length: count }, (_, index) => `line ${index + 1}`).join("\n")
+}
+
+function rowPairPlan(
+  regions: Record<"shell" | "following", { selector: string; closest?: string }>,
+  maxPositionReversals: number,
+) {
+  return visualPlan(regions, [
+    { type: "required", regions: ["shell", "following"] },
+    { type: "unique", regions: ["shell", "following"] },
+    { type: "stable", regions: ["shell", "following"] },
+    { type: "opacity", regions: "all" },
+    { type: "continuity", regions: "all" },
+    { type: "motion", regions: "all", maxPositionReversals },
+    { type: "label-stability", regions: "all" },
+    { type: "flow", regions: ["shell", "following"] },
+  ])
+}
+
+function anchorPlan(regions: Record<"anchor", { selector: string; closest?: string }>) {
+  return visualPlan(regions, [
+    { type: "required", regions: ["anchor"] },
+    { type: "unique", regions: ["anchor"] },
+    { type: "stable", regions: ["anchor"] },
+    { type: "fixed", regions: ["anchor"] },
+    { type: "opacity", regions: "all" },
+    { type: "continuity", regions: "all" },
+    { type: "motion", regions: "all", maxPositionReversals: 0 },
+    { type: "label-stability", regions: "all" },
+  ])
+}

packages/app/e2e/performance/timeline-stability/shell-matrix.spec.ts

@@ -0,0 +1,255 @@
+import { test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import {
+  assistantMessage,
+  partUpdated,
+  setupTimeline,
+  shell,
+  textPart,
+  userMessage,
+  waitForVisualSettle,
+} from "./fixture"
+
+const profiles = [
+  {
+    name: "empty running to completed",
+    updates: [{ state: "completed" as const, output: "", delay: 350 }],
+  },
+  {
+    name: "50 lines arriving incrementally",
+    updates: [
+      { state: "running" as const, output: lines(1), delay: 100 },
+      { state: "running" as const, output: lines(10), delay: 160 },
+      { state: "running" as const, output: lines(25), delay: 90 },
+      { state: "running" as const, output: lines(50), delay: 220 },
+      { state: "completed" as const, output: lines(50), delay: 500 },
+    ],
+  },
+  {
+    name: "wide ANSI and CRLF output",
+    updates: [
+      {
+        state: "running" as const,
+        output: Array.from({ length: 20 }, (_, index) => `\u001b[32mline ${index}\u001b[0m ${"wide-".repeat(30)}`).join(
+          "\r\n",
+        ),
+        delay: 240,
+      },
+      {
+        state: "completed" as const,
+        output: Array.from({ length: 20 }, (_, index) => `line ${index} ${"wide-".repeat(30)}`).join("\n"),
+        delay: 500,
+      },
+    ],
+  },
+] as const
+
+for (const profile of profiles) {
+  test(`keeps rows stable for shell ${profile.name}`, async ({ page }, testInfo) => {
+    const shellID = `prt_matrix_${profiles.indexOf(profile)}_01_shell`
+    const followingID = `prt_matrix_${profiles.indexOf(profile)}_02_following`
+    const timeline = await setupTimeline(page, {
+      messages: [
+        userMessage(),
+        assistantMessage([shell(shellID, "running"), textPart(followingID, "Following shell row")], {
+          completed: false,
+        }),
+      ],
+      settings: { shellToolPartsExpanded: true },
+      cpuRate: 4,
+      seedHistory: true,
+    })
+    const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
+    await scroller.evaluate((element) => (element.scrollTop = element.scrollHeight))
+    await waitForVisualSettle(page, [
+      `[data-timeline-part-id="${shellID}"]`,
+      `[data-timeline-part-id="${followingID}"]`,
+    ])
+    const regions = defineVisualRegions({
+      shell: { selector: `[data-timeline-part-id="${shellID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+      following: {
+        selector: `[data-timeline-part-id="${followingID}"]`,
+        closest: '[data-timeline-row="AssistantPart"]',
+      },
+    })
+    await startVisualProbe(page, regions)
+    for (const update of profile.updates) {
+      await timeline.send(partUpdated(shell(shellID, update.state, update.output)), update.delay)
+    }
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    await reportVisualStability(
+      testInfo,
+      `shell-${profiles.indexOf(profile)}`,
+      trace,
+      visualPlan(
+        regions,
+        [
+          { type: "required", regions: ["shell", "following"] },
+          { type: "unique", regions: ["shell", "following"] },
+          { type: "stable", regions: ["shell", "following"] },
+          { type: "opacity", regions: "all" },
+          { type: "continuity", regions: "all" },
+          { type: "motion", regions: "all", maxPositionReversals: 0, maxReversals: 1 },
+          { type: "label-stability", regions: "all" },
+          { type: "preserve-bottom-anchor" },
+          { type: "flow", regions: ["shell", "following"] },
+        ],
+        { perMarker: true },
+      ),
+    )
+  })
+}
+
+test("keeps following row stable when a collapsed shell receives 50 lines", async ({ page }, testInfo) => {
+  const shellID = "prt_matrix_collapsed_01_shell"
+  const followingID = "prt_matrix_collapsed_02_following"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([shell(shellID, "running"), textPart(followingID, "Following collapsed shell")], {
+        completed: false,
+      }),
+    ],
+    settings: { shellToolPartsExpanded: false },
+    cpuRate: 4,
+    seedHistory: true,
+  })
+  await waitForVisualSettle(page, [`[data-timeline-part-id="${shellID}"]`, `[data-timeline-part-id="${followingID}"]`])
+  const regions = defineVisualRegions({
+    shell: { selector: `[data-timeline-part-id="${shellID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(partUpdated(shell(shellID, "running", lines(50))), 240)
+  await timeline.send(partUpdated(shell(shellID, "completed", lines(50))), 500)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "collapsed-shell",
+    trace,
+    visualPlan(
+      regions,
+      [
+        { type: "required", regions: ["shell", "following"] },
+        { type: "unique", regions: ["shell", "following"] },
+        { type: "stable", regions: ["shell", "following"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: ["following"], maxPositionReversals: 0 },
+        { type: "label-stability", regions: "all" },
+        { type: "flow", regions: ["shell", "following"] },
+      ],
+      { perMarker: true },
+    ),
+  )
+})
+
+test("keeps rows stable when a running shell becomes an error", async ({ page }, testInfo) => {
+  const shellID = "prt_matrix_error_01_shell"
+  const followingID = "prt_matrix_error_02_following"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([shell(shellID, "running", lines(10)), textPart(followingID, "Following failed shell")], {
+        completed: false,
+      }),
+    ],
+    settings: { shellToolPartsExpanded: true },
+    cpuRate: 4,
+    seedHistory: true,
+  })
+  await waitForVisualSettle(page, [`[data-timeline-part-id="${shellID}"]`, `[data-timeline-part-id="${followingID}"]`])
+  const regions = defineVisualRegions({
+    shell: { selector: `[data-timeline-part-id="${shellID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(
+    partUpdated({
+      ...shell(shellID, "error"),
+      state: {
+        status: "error",
+        input: { command: `echo ${shellID}` },
+        error: "Command failed after output",
+        metadata: {},
+        time: { start: 1700000001000, end: 1700000002000 },
+      },
+    }),
+    500,
+  )
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "shell-error",
+    trace,
+    visualPlan(
+      regions,
+      [
+        { type: "required", regions: ["shell", "following"] },
+        { type: "unique", regions: ["shell", "following"] },
+        { type: "stable", regions: ["shell", "following"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: ["following"], maxPositionReversals: 0 },
+        { type: "label-stability", regions: "all" },
+        { type: "preserve-bottom-anchor" },
+        { type: "flow", regions: ["shell", "following"] },
+      ],
+      { perMarker: true },
+    ),
+  )
+})
+
+test("keeps rows stable when later text arrives before shell output", async ({ page }, testInfo) => {
+  const shellID = "prt_late_text_01_shell"
+  const followingID = "prt_late_text_02_following"
+  const timeline = await setupTimeline(page, {
+    messages: [userMessage(), assistantMessage([shell(shellID, "running")], { completed: false })],
+    settings: { shellToolPartsExpanded: true },
+    cpuRate: 4,
+    seedHistory: true,
+  })
+  await waitForVisualSettle(page, [`[data-timeline-part-id="${shellID}"]`])
+  const regions = defineVisualRegions({
+    shell: { selector: `[data-timeline-part-id="${shellID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    following: {
+      selector: `[data-timeline-part-id="${followingID}"]`,
+      closest: '[data-timeline-row="AssistantPart"]',
+    },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(partUpdated(textPart(followingID, "Later assistant content arrived before shell output.")), 240)
+  await timeline.send(partUpdated(shell(shellID, "running", lines(20))), 300)
+  await timeline.send(partUpdated(shell(shellID, "completed", lines(20))), 600)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "late-text-before-shell-output",
+    trace,
+    visualPlan(
+      regions,
+      [
+        { type: "required", regions: ["shell", "following"] },
+        { type: "unique", regions: ["shell", "following"] },
+        { type: "stable", regions: ["shell"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all", maxPositionReversals: 0 },
+        { type: "label-stability", regions: "all" },
+        { type: "preserve-bottom-anchor" },
+        { type: "flow", regions: ["shell", "following"] },
+      ],
+      { perMarker: true },
+    ),
+  )
+})
+
+function lines(count: number) {
+  return Array.from({ length: count }, (_, index) => `line ${index + 1}`).join("\n")
+}

packages/app/e2e/performance/timeline-stability/tool-mutation.spec.ts

@@ -0,0 +1,106 @@
+import { expect, test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import {
+  assistantMessage,
+  partUpdated,
+  session,
+  sessionID,
+  setupTimeline,
+  textPart,
+  toolPart,
+  userMessage,
+} from "./fixture"
+
+test("adds a task child-session link without replacing the task row", async ({ page }, testInfo) => {
+  const taskID = "prt_task_link"
+  const childID = "ses_task_child"
+  const input = { description: "Inspect child", subagent_type: "explore" }
+  const timeline = await setupTimeline(page, {
+    messages: [userMessage(), assistantMessage([toolPart(taskID, "task", "running", input)], { completed: false })],
+    sessions: [session(), session({ id: childID, parentID: sessionID, title: "Inspect child" })],
+    cpuRate: 4,
+  })
+  const regions = defineVisualRegions({
+    task: { selector: `[data-timeline-part-id="${taskID}"] [data-slot="collapsible-trigger"]` },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(
+    partUpdated(toolPart(taskID, "task", "completed", input, { metadata: { sessionId: childID } })),
+    500,
+  )
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "task-link",
+    trace,
+    visualPlan(regions, [
+      { type: "required", regions: ["task"] },
+      { type: "unique", regions: ["task"] },
+      { type: "stable", regions: ["task"] },
+      { type: "opacity", regions: "all" },
+      { type: "continuity", regions: "all" },
+      { type: "motion", regions: "all", maxPositionReversals: 0 },
+      { type: "label-stability", regions: "all" },
+    ]),
+  )
+  await expect(
+    page.locator(`a[href$="/session/${childID}"]`, { has: page.locator('[data-component="task-tool-card"]') }),
+  ).toBeVisible()
+})
+
+test("changes generic tool arguments without replacing the row", async ({ page }, testInfo) => {
+  const toolID = "prt_generic_mutation"
+  const followingID = "prt_generic_mutation_following"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage(
+        [
+          toolPart(toolID, "mcp_probe", "running", { target: "one", count: 1 }),
+          textPart(followingID, "Following generic tool"),
+        ],
+        { completed: false },
+      ),
+    ],
+    cpuRate: 4,
+  })
+  const regions = defineVisualRegions({
+    tool: { selector: `[data-timeline-part-id="${toolID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(
+    partUpdated(toolPart(toolID, "mcp_probe", "running", { target: "two", count: 2, mode: "deep" })),
+    200,
+  )
+  await timeline.send(
+    partUpdated(toolPart(toolID, "mcp_probe", "completed", { target: "two", count: 2, mode: "deep" })),
+    400,
+  )
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "generic-mutation",
+    trace,
+    visualPlan(
+      regions,
+      [
+        { type: "required", regions: ["tool", "following"] },
+        { type: "unique", regions: ["tool", "following"] },
+        { type: "stable", regions: ["tool", "following"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all", maxPositionReversals: 0 },
+        { type: "label-stability", regions: "all" },
+        { type: "flow", regions: ["tool", "following"] },
+      ],
+      { perMarker: true },
+    ),
+  )
+})

packages/app/e2e/performance/timeline-stability/tools.spec.ts

@@ -0,0 +1,198 @@
+import { expect, test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import {
+  assistantMessage,
+  directory,
+  partUpdated,
+  session,
+  sessionID,
+  setupTimeline,
+  status,
+  textPart,
+  toolPart,
+  userMessage,
+} from "./fixture"
+
+test.describe("timeline tool state stability", () => {
+  test("moves lightweight tools through pending, running, and completed without replacing rows", async ({
+    page,
+  }, testInfo) => {
+    const ids = ["webfetch", "websearch", "task", "skill", "custom"] as const
+    const inputs = {
+      webfetch: { url: "https://example.com/docs" },
+      websearch: { query: "timeline stability" },
+      task: { description: "Inspect timeline", subagent_type: "explore" },
+      skill: { name: "stability" },
+      custom: { target: "timeline", depth: 2 },
+    }
+    const names = { webfetch: "webfetch", websearch: "websearch", task: "task", skill: "skill", custom: "mcp_probe" }
+    const questionID = "prt_state_question"
+    const todoID = "prt_state_todo"
+    const initial = [
+      ...ids.map((id) => toolPart(`prt_state_${id}`, names[id], "pending", inputs[id])),
+      toolPart(questionID, "question", "pending", questionInput()),
+      toolPart(todoID, "todowrite", "pending", { todos: [{ content: "Hidden", status: "pending" }] }),
+      textPart("prt_state_following", "Following lightweight tools"),
+    ]
+    const childID = "ses_timeline_child"
+    const timeline = await setupTimeline(page, {
+      messages: [userMessage(), assistantMessage(initial, { completed: false })],
+      sessions: [session(), session({ id: childID, parentID: sessionID, title: "Inspect timeline" })],
+      cpuRate: 4,
+    })
+    await timeline.send(status("busy"), 120)
+    for (const id of ids) await timeline.waitForPart(`prt_state_${id}`)
+    await expect(page.locator(`[data-timeline-part-id="${questionID}"]`)).toHaveCount(0)
+    await expect(page.locator(`[data-timeline-part-id="${todoID}"]`)).toHaveCount(0)
+
+    const regionIDs = [
+      "prt_state_webfetch",
+      "prt_state_websearch",
+      "prt_state_task",
+      "prt_state_skill",
+      "prt_state_custom",
+    ] as const
+    const regions = defineVisualRegions({
+      prt_state_webfetch: toolRegion(regionIDs[0]),
+      prt_state_websearch: toolRegion(regionIDs[1]),
+      prt_state_task: toolRegion(regionIDs[2]),
+      prt_state_skill: toolRegion(regionIDs[3]),
+      prt_state_custom: toolRegion(regionIDs[4]),
+    })
+    await startVisualProbe(page, regions)
+    for (const [index, id] of ids.entries()) {
+      await timeline.send(
+        partUpdated(toolPart(`prt_state_${id}`, names[id], "running", inputs[id])),
+        [80, 240, 100, 360, 140][index],
+      )
+    }
+    for (const [index, id] of ["skill", "webfetch", "custom", "task", "websearch"].entries()) {
+      const key = id as (typeof ids)[number]
+      const metadata = key === "task" ? { sessionId: childID } : key === "websearch" ? { provider: "exa" } : {}
+      const output = key === "websearch" ? "Result https://example.com/result" : "Completed"
+      await timeline.send(
+        partUpdated(toolPart(`prt_state_${key}`, names[key], "completed", inputs[key], { metadata, output })),
+        [110, 70, 280, 130, 420][index],
+      )
+    }
+    await timeline.send(
+      partUpdated(
+        toolPart(questionID, "question", "completed", questionInput(), { metadata: { answers: [["Keep it stable"]] } }),
+      ),
+      350,
+    )
+    await timeline.waitForPart(questionID)
+    await timeline.send(status("idle"), 500)
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    await reportVisualStability(
+      testInfo,
+      "lightweight-tools",
+      trace,
+      visualPlan(regions, [
+        { type: "required", regions: regionIDs },
+        { type: "unique", regions: regionIDs },
+        { type: "stable", regions: regionIDs },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all", maxReversals: 4 },
+        { type: "label-stability", regions: "all" },
+      ]),
+    )
+    await expect(page.locator(`[data-timeline-part-id="${questionID}"]`)).toContainText("Keep it stable")
+    await expect(page.locator(`[data-timeline-part-id="${todoID}"]`)).toHaveCount(0)
+    await expect(
+      page.locator(`a[href$="/session/${childID}"]`, { has: page.locator('[data-component="task-tool-card"]') }),
+    ).toBeVisible()
+    await expect(page.getByRole("button", { name: /Exa Web Search/ })).toBeVisible()
+  })
+
+  test("keeps an expanded mixed context group stable through staggered completion and error", async ({
+    page,
+  }, testInfo) => {
+    const ids = ["prt_ctx_01_read", "prt_ctx_02_glob", "prt_ctx_03_grep", "prt_ctx_04_list"]
+    const tools = ["read", "glob", "grep", "list"]
+    const inputs = [
+      { filePath: "src/a.ts", offset: 0, limit: 120 },
+      { path: directory, pattern: "**/*.ts" },
+      { path: directory, pattern: "stability", include: "*.ts" },
+      { path: "src" },
+    ]
+    const context = ids.map((id, index) => toolPart(id, tools[index]!, "pending", inputs[index]!))
+    const timeline = await setupTimeline(page, {
+      messages: [
+        userMessage(),
+        assistantMessage([...context, textPart("prt_ctx_following", "Following context")], { completed: false }),
+      ],
+      cpuRate: 4,
+    })
+    await timeline.send(status("busy"), 100)
+    const groupSelector = `[data-timeline-part-ids="${ids.join(",")}"]`
+    const group = page.locator(groupSelector)
+    await expect(group).toBeVisible()
+    await group.locator('[data-slot="collapsible-trigger"]').click()
+    await expect(group.locator('[data-slot="collapsible-trigger"]')).toHaveAttribute("aria-expanded", "true")
+
+    const regions = defineVisualRegions({
+      status: {
+        selector: `${groupSelector} [data-component="tool-status-title"]`,
+        opacitySelectors: ['[data-slot="tool-status-active"]', '[data-slot="tool-status-done"]'],
+      },
+      context: { selector: groupSelector, closest: '[data-timeline-row="AssistantPart"]' },
+      following: {
+        selector: '[data-timeline-part-id="prt_ctx_following"]',
+        closest: '[data-timeline-row="AssistantPart"]',
+      },
+    })
+    await startVisualProbe(page, regions)
+    for (const [index, delay] of [90, 260, 70, 380].entries()) {
+      await timeline.send(partUpdated(toolPart(ids[index]!, tools[index]!, "running", inputs[index]!)), delay)
+    }
+    await timeline.send(partUpdated(toolPart(ids[1]!, tools[1]!, "completed", inputs[1]!)), 130)
+    await timeline.send(partUpdated(toolPart(ids[3]!, tools[3]!, "completed", inputs[3]!)), 210)
+    await timeline.send(
+      partUpdated(toolPart(ids[0]!, tools[0]!, "error", inputs[0]!, { error: "Read interrupted" })),
+      110,
+    )
+    await timeline.send(partUpdated(toolPart(ids[2]!, tools[2]!, "completed", inputs[2]!)), 250)
+    await expect(group.locator('[data-component="tool-status-title"]')).toHaveAttribute("aria-label", "Explored")
+    await timeline.send(status("idle"), 700)
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    await reportVisualStability(
+      testInfo,
+      "mixed-context",
+      trace,
+      visualPlan(regions, [
+        { type: "required", regions: ["context", "following"] },
+        { type: "unique", regions: ["context"] },
+        { type: "stable", regions: ["context"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all", maxReversals: 4 },
+        { type: "label-stability", regions: "all" },
+        { type: "flow", regions: ["context", "following"] },
+      ]),
+    )
+    await expect(group.locator('[data-component="tool-status-title"]')).toHaveAttribute("aria-label", "Explored")
+    await expect(group.locator('[data-slot="collapsible-trigger"]')).toHaveAttribute("aria-expanded", "true")
+    await group.locator('[data-slot="collapsible-trigger"]').click()
+    await expect(group.locator('[data-slot="collapsible-trigger"]')).toHaveAttribute("aria-expanded", "false")
+    await timeline.send(partUpdated(textPart("prt_ctx_late_sibling", "Later sibling content")), 200)
+    await expect(group.locator('[data-slot="collapsible-trigger"]')).toHaveAttribute("aria-expanded", "false")
+    await group.locator('[data-slot="collapsible-trigger"]').click()
+    await expect(group.locator('[data-slot="collapsible-trigger"]')).toHaveAttribute("aria-expanded", "true")
+  })
+})
+
+function questionInput() {
+  return { questions: [{ header: "Stability", question: "Keep it stable?", options: [] }] }
+}
+
+function toolRegion(id: string) {
+  return { selector: `[data-timeline-part-id="${id}"]`, closest: '[data-timeline-row="AssistantPart"]' }
+}

packages/app/e2e/performance/timeline-stability/transition-matrix.spec.ts

@@ -0,0 +1,272 @@
+import { expect, test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import {
+  assistantID,
+  assistantMessage,
+  completedAssistantInfo,
+  event,
+  messageUpdated,
+  partDelta,
+  partUpdated,
+  setupTimeline,
+  shell,
+  status,
+  textPart,
+  toolPart,
+  userMessage,
+} from "./fixture"
+
+test("keeps unchanged siblings stable while a middle part is inserted and removed", async ({ page }, testInfo) => {
+  const firstID = "prt_mutation_01_first"
+  const middleID = "prt_mutation_02_middle"
+  const lastID = "prt_mutation_03_last"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([textPart(firstID, "First stable row"), textPart(lastID, "Last stable row")], {
+        completed: false,
+      }),
+    ],
+    cpuRate: 4,
+  })
+  const regions = defineVisualRegions({
+    first: { selector: `[data-timeline-part-id="${firstID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    last: { selector: `[data-timeline-part-id="${lastID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(partUpdated(textPart(middleID, "Inserted middle row. ".repeat(12))), 350)
+  await expect(page.locator(`[data-timeline-part-id="${middleID}"]`)).toBeVisible()
+  await timeline.send(
+    event("message.part.removed", { sessionID: "ses_timeline_stability", messageID: assistantID, partID: middleID }),
+    500,
+  )
+  await expect(page.locator(`[data-timeline-part-id="${middleID}"]`)).toHaveCount(0)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(testInfo, "middle-insert-remove", trace, stablePairPlan(regions, 1))
+})
+
+test("streams text through growth, canonical replacement, and completion", async ({ page }, testInfo) => {
+  const textID = "prt_text_reconcile"
+  const followingID = "prt_text_reconcile_following"
+  const assistant = assistantMessage([textPart(textID, "Starting"), textPart(followingID, "Following text row")], {
+    completed: false,
+  })
+  const timeline = await setupTimeline(page, { messages: [userMessage(), assistant], cpuRate: 4 })
+  const regions = defineVisualRegions({
+    text: { selector: `[data-timeline-part-id="${textID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(partDelta(textID, " streamed content"), 100)
+  await timeline.send(partDelta(textID, "\n\n- item one\n- item two\n- item three"), 180)
+  await timeline.send(partUpdated(textPart(textID, "Canonical replacement with a shorter final paragraph.")), 200)
+  await timeline.send(messageUpdated(completedAssistantInfo(assistant.info)), 500)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "text-reconcile",
+    trace,
+    visualPlan(regions, [
+      { type: "required", regions: ["text", "following"] },
+      { type: "unique", regions: ["text", "following"] },
+      { type: "stable", regions: ["text", "following"] },
+      { type: "opacity", regions: "all" },
+      { type: "continuity", regions: "all" },
+      { type: "motion", regions: "all", maxPositionReversals: 1, maxReversals: 2 },
+      { type: "label-stability", regions: "all" },
+      { type: "preserve-bottom-anchor" },
+      { type: "flow", regions: ["text", "following"] },
+    ]),
+  )
+})
+
+test("inserts a completed question between stable rows", async ({ page }, testInfo) => {
+  const firstID = "prt_question_01_first"
+  const questionID = "prt_question_02_hidden"
+  const lastID = "prt_question_03_last"
+  const input = { questions: [{ header: "Choice", question: "Keep stable?", options: [] }] }
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage(
+        [
+          textPart(firstID, "Before question"),
+          toolPart(questionID, "question", "running", input),
+          textPart(lastID, "After question"),
+        ],
+        { completed: false },
+      ),
+    ],
+    cpuRate: 4,
+  })
+  await expect(page.locator(`[data-timeline-part-id="${questionID}"]`)).toHaveCount(0)
+  const regions = defineVisualRegions({
+    first: { selector: `[data-timeline-part-id="${firstID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    last: { selector: `[data-timeline-part-id="${lastID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(
+    partUpdated(toolPart(questionID, "question", "completed", input, { metadata: { answers: [["Yes"]] } })),
+    600,
+  )
+  await expect(page.locator(`[data-timeline-part-id="${questionID}"]`)).toBeVisible()
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(testInfo, "question-insert", trace, stablePairPlan(regions, 0))
+})
+
+test("replaces thinking with an assistant error without a blank turn", async ({ page }, testInfo) => {
+  const assistant = assistantMessage([], { completed: false })
+  const timeline = await setupTimeline(page, { messages: [userMessage(), assistant], cpuRate: 4 })
+  await timeline.send(status("busy"), 150)
+  await expect(page.locator('[data-timeline-row="Thinking"]')).toBeVisible()
+  const regions = defineVisualRegions({
+    thinking: { selector: '[data-timeline-row="Thinking"]' },
+    error: { selector: '[data-timeline-row="Error"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(
+    messageUpdated({
+      ...assistant.info,
+      error: { name: "APIError", data: { message: "Provider failed visibly", isRetryable: false } },
+    }),
+    500,
+  )
+  await expect(page.locator('[data-timeline-row="Thinking"]')).toHaveCount(0)
+  await expect(page.locator('[data-timeline-row="Error"]')).toContainText("Provider failed visibly")
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "thinking-error",
+    trace,
+    visualPlan(regions, [
+      { type: "required", regions: ["thinking", "error"] },
+      { type: "continuous-any", regions: ["thinking", "error"] },
+      { type: "unique", regions: ["thinking", "error"] },
+      { type: "opacity", regions: "all" },
+      { type: "continuity", regions: "all" },
+      { type: "motion", regions: "all" },
+      { type: "label-stability", regions: "all" },
+    ]),
+  )
+})
+
+test("updates retry attempts and long provider messages without remounting the retry row", async ({
+  page,
+}, testInfo) => {
+  const timeline = await setupTimeline(page, {
+    messages: [userMessage(), assistantMessage([], { completed: false })],
+    cpuRate: 4,
+  })
+  await timeline.send(status("retry", 1), 120)
+  await expect(page.locator('[data-timeline-row="Retry"]')).toBeVisible()
+  const regions = defineVisualRegions({
+    retry: { selector: '[data-timeline-row="Retry"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(
+    event("session.status", {
+      sessionID: "ses_timeline_stability",
+      status: {
+        type: "retry",
+        attempt: 2,
+        message: "A very long provider retry message ".repeat(8),
+        next: Date.now() + 10_000,
+      },
+    }),
+    300,
+  )
+  await timeline.send(status("retry", 3), 300)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "retry-evolution",
+    trace,
+    visualPlan(
+      regions,
+      [
+        { type: "required", regions: ["retry"] },
+        { type: "unique", regions: ["retry"] },
+        { type: "stable", regions: ["retry"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all", maxPositionReversals: 0 },
+        { type: "label-stability", regions: "all" },
+      ],
+      { perMarker: true },
+    ),
+  )
+})
+
+test("reducer-hardening: removes a historical turn one message at a time without moving a visible lower anchor twice", async ({
+  page,
+}, testInfo) => {
+  const removeUserID = "msg_0500_remove_user"
+  const removeAssistantID = "msg_0501_remove_assistant"
+  const anchorUserID = "msg_2000_anchor_user"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(undefined, { id: removeUserID, created: 1690000000000 }),
+      assistantMessage([textPart("prt_remove_text", "Removed historical content. ".repeat(15))], {
+        id: removeAssistantID,
+        parentID: removeUserID,
+        created: 1690000001000,
+      }),
+      userMessage(undefined, { id: anchorUserID, created: 1700000000000 }),
+      assistantMessage([textPart("prt_anchor_text", "Visible anchor response")], {
+        id: "msg_2001_anchor_assistant",
+        parentID: anchorUserID,
+        created: 1700000001000,
+      }),
+    ],
+    cpuRate: 4,
+  })
+  const regions = defineVisualRegions({
+    anchor: { selector: `[data-timeline-row="UserMessage"][data-message-id="${anchorUserID}"]` },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(
+    event("message.removed", { sessionID: "ses_timeline_stability", messageID: removeAssistantID }),
+    200,
+  )
+  await timeline.send(event("message.removed", { sessionID: "ses_timeline_stability", messageID: removeUserID }), 500)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "historical-turn-remove",
+    trace,
+    visualPlan(
+      regions,
+      [
+        { type: "required", regions: ["anchor"] },
+        { type: "unique", regions: ["anchor"] },
+        { type: "stable", regions: ["anchor"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all", maxPositionReversals: 0 },
+        { type: "label-stability", regions: "all" },
+      ],
+      { perMarker: true },
+    ),
+  )
+})
+
+function stablePairPlan(
+  regions: Record<"first" | "last", { selector: string; closest?: string }>,
+  maxPositionReversals: number,
+) {
+  return visualPlan(regions, [
+    { type: "required", regions: ["first", "last"] },
+    { type: "unique", regions: ["first", "last"] },
+    { type: "stable", regions: ["first", "last"] },
+    { type: "opacity", regions: "all" },
+    { type: "continuity", regions: "all" },
+    { type: "motion", regions: "all", maxPositionReversals },
+    { type: "label-stability", regions: "all" },
+  ])
+}

packages/app/e2e/performance/timeline/first-navigation-benchmark.spec.ts

@@ -0,0 +1,87 @@
+import { expectSessionTitle } from "../../utils/waits"
+import { benchmark, expect } from "../benchmark"
+import { measureFirstNavigation } from "./first-navigation-probe"
+import { fixture } from "./session-timeline-stress.fixture"
+import {
+  installStressSessionTabs,
+  installTimelineSettings,
+  mockStressTimeline,
+  stressDraftHref,
+  stressSessionHref,
+} from "./timeline-test-helpers"
+import { waitForStableTimeline } from "./session-tab-switch-probe"
+
+const contentSelector = '[data-message-id], [data-component="prompt-input"]'
+const draftID = "draft_first_navigation"
+
+benchmark.describe("performance: first navigation paint", () => {
+  benchmark("opens an unvisited session tab without a blank frame", async ({ page, report }) => {
+    await setup(page)
+    const href = stressSessionHref(fixture.targetID)
+    const result = await measureFirstNavigation(page, {
+      href,
+      destinationPath: href,
+      sourceSelector: messageSelector(fixture.expected.sourceMessageIDs.at(-1)!),
+      destinationSelector: messageSelector(fixture.expected.targetMessageIDs.at(-1)!),
+      contentSelector,
+      navigate: async () => {
+        await page.locator(`[data-slot="titlebar-tabs"] a[href="${href}"]`).first().click()
+        await expectSessionTitle(page, fixture.expected.targetTitle)
+      },
+    })
+    report(result)
+    expect(result.summary.blankSamples).toBe(0)
+    expect(result.summary.unknownSamples).toBe(0)
+  })
+
+  benchmark("opens the new session page before its lazy module is used", async ({ page, report }) => {
+    await setup(page, draftID)
+    const href = stressDraftHref(draftID)
+    const result = await measureFirstNavigation(page, {
+      href,
+      destinationPath: href,
+      sourceSelector: messageSelector(fixture.expected.sourceMessageIDs.at(-1)!),
+      destinationSelector: '[data-component="prompt-input"]',
+      contentSelector,
+      navigate: async () => {
+        await page.locator(`[data-slot="titlebar-tabs"] a[href="${href}"]`).first().click()
+        await expect(page.locator('[data-component="prompt-input"]')).toBeVisible()
+      },
+    })
+    report(result)
+    expect(result.summary.blankSamples).toBe(0)
+    expect(result.summary.unknownSamples).toBe(0)
+  })
+
+  benchmark("opens a child session without a blank frame", async ({ page, report }) => {
+    await setup(page)
+    const href = stressSessionHref(fixture.childID)
+    const result = await measureFirstNavigation(page, {
+      href,
+      destinationPath: href,
+      sourceSelector: messageSelector(fixture.expected.sourceMessageIDs.at(-1)!),
+      destinationSelector: messageSelector(fixture.expected.childMessageIDs.at(-1)!),
+      contentSelector,
+      navigate: async () => {
+        await page.locator(`a[href="${href}"]`, { has: page.locator('[data-component="task-tool-card"]') }).click()
+        await expectSessionTitle(page, fixture.expected.childTitle)
+      },
+    })
+    report(result)
+    expect(result.summary.blankSamples).toBe(0)
+    expect(result.summary.unknownSamples).toBe(0)
+  })
+})
+
+async function setup(page: Parameters<typeof mockStressTimeline>[0], draft?: string) {
+  await mockStressTimeline(page)
+  await installTimelineSettings(page)
+  await installStressSessionTabs(page, draft ? { draftID: draft } : undefined)
+  await page.goto(stressSessionHref(fixture.sourceID))
+  await expectSessionTitle(page, fixture.expected.sourceTitle)
+  await waitForStableTimeline(page, fixture.expected.sourceMessageIDs.at(-1)!)
+}
+
+function messageSelector(id: string) {
+  return `[data-message-id="${id}"]`
+}

packages/app/e2e/performance/timeline/first-navigation-metrics.ts

@@ -0,0 +1,32 @@
+export type FirstNavigationSample = {
+  observedAtMs: number
+  source: boolean
+  destination: boolean
+  content: boolean
+  pathname?: string
+  center?: string
+}
+
+function category(sample: FirstNavigationSample) {
+  if (sample.destination && !sample.source) return "destination"
+  if (sample.source && !sample.destination) return "source"
+  if (!sample.content) return "blank"
+  return "unknown"
+}
+
+export function summarizeFirstNavigation(samples: FirstNavigationSample[]) {
+  const categories = samples.map(category)
+  const stable = categories.findIndex(
+    (value, index) =>
+      value === "destination" && categories[index + 1] === "destination" && categories[index + 2] === "destination",
+  )
+  return {
+    samples: samples.length,
+    firstDestinationObservedMs: samples[categories.indexOf("destination")]?.observedAtMs ?? null,
+    stableDestinationObservedMs: stable === -1 ? null : samples[stable + 2]!.observedAtMs,
+    sourceSamples: categories.filter((value) => value === "source").length,
+    blankSamples: categories.filter((value) => value === "blank").length,
+    unknownSamples: categories.filter((value) => value === "unknown").length,
+    destinationSamples: categories.filter((value) => value === "destination").length,
+  }
+}

packages/app/e2e/performance/timeline/first-navigation-probe.ts

@@ -0,0 +1,86 @@
+import type { Page } from "@playwright/test"
+import { summarizeFirstNavigation, type FirstNavigationSample } from "./first-navigation-metrics"
+
+type FirstNavigationProbe = {
+  samples: FirstNavigationSample[]
+  stop: () => void
+}
+
+export async function measureFirstNavigation(
+  page: Page,
+  input: {
+    href: string
+    destinationPath: string
+    sourceSelector: string
+    destinationSelector: string
+    contentSelector: string
+    navigate: () => Promise<void>
+  },
+) {
+  await page.evaluate(
+    ({ href, destinationPath, sourceSelector, destinationSelector, contentSelector }) => {
+      const samples: FirstNavigationSample[] = []
+      let started: number | undefined
+      let running = true
+      const visible = (selector: string) =>
+        [...document.querySelectorAll<HTMLElement>(selector)].some((element) => {
+          const rect = element.getBoundingClientRect()
+          const style = getComputedStyle(element)
+          return rect.width > 0 && rect.height > 0 && style.visibility !== "hidden" && style.display !== "none"
+        })
+      const sample = () => {
+        if (!running || started === undefined) return
+        requestAnimationFrame(() => {
+          setTimeout(() => {
+            if (!running || started === undefined) return
+            samples.push({
+              observedAtMs: performance.now() - started,
+              source: visible(sourceSelector),
+              destination: `${location.pathname}${location.search}` === destinationPath && visible(destinationSelector),
+              content: visible(contentSelector),
+              pathname: `${location.pathname}${location.search}`,
+              center: document.elementFromPoint(innerWidth / 2, innerHeight / 2)?.textContent?.slice(0, 80),
+            })
+            sample()
+          }, 0)
+        })
+      }
+      document.addEventListener(
+        "click",
+        (event) => {
+          const link = event.target instanceof Element ? event.target.closest("a") : undefined
+          if (link?.getAttribute("href") !== href) return
+          started = performance.now()
+          sample()
+        },
+        { capture: true, once: true },
+      )
+      ;(window as Window & { __firstNavigationProbe?: FirstNavigationProbe }).__firstNavigationProbe = {
+        samples,
+        stop: () => {
+          running = false
+        },
+      }
+    },
+    {
+      href: input.href,
+      destinationPath: input.destinationPath,
+      sourceSelector: input.sourceSelector,
+      destinationSelector: input.destinationSelector,
+      contentSelector: input.contentSelector,
+    },
+  )
+  await input.navigate()
+  await page.waitForFunction(() => {
+    const samples = (window as Window & { __firstNavigationProbe?: FirstNavigationProbe }).__firstNavigationProbe
+      ?.samples
+    if (!samples) return false
+    return samples.length >= 3 && samples.slice(-3).every((sample) => sample.destination && !sample.source)
+  })
+  const samples = await page.evaluate(() => {
+    const probe = (window as Window & { __firstNavigationProbe?: FirstNavigationProbe }).__firstNavigationProbe!
+    probe.stop()
+    return probe.samples
+  })
+  return { summary: summarizeFirstNavigation(samples), samples }
+}

packages/app/e2e/performance/timeline/home-tab-navigation-benchmark.spec.ts

@@ -0,0 +1,114 @@
+import { benchmark, expect } from "../benchmark"
+import { expectSessionTitle } from "../../utils/waits"
+import { measureNavigationMilestones } from "./navigation-milestones"
+import { fixture } from "./session-timeline-stress.fixture"
+import {
+  installStressSessionTabs,
+  installTimelineSettings,
+  mockStressTimeline,
+  stressSessionHref,
+} from "./timeline-test-helpers"
+import { waitForStableTimeline } from "./session-tab-switch-probe"
+
+const homeRow = '[data-component="home-session-row"]'
+const homeShell = '[data-component="home-session-search"]'
+
+benchmark.describe("performance: home and tab navigation", () => {
+  benchmark("opens a home session and paints its titlebar tab", async ({ page, report }) => {
+    await setup(page, [])
+    await page.goto("/")
+    const row = page.locator(homeRow).filter({ hasText: fixture.expected.targetTitle }).first()
+    await expect(row).toBeVisible()
+    const href = stressSessionHref(fixture.targetID)
+    const result = await measureNavigationMilestones(page, {
+      triggerSelector: homeRow,
+      milestones: {
+        content: { selector: messageSelector(fixture.expected.targetMessageIDs.at(-1)!) },
+        tab: { selector: `[data-slot="titlebar-tabs"] a[href="${href}"]` },
+      },
+      navigate: async () => {
+        await row.click()
+        await expectSessionTitle(page, fixture.expected.targetTitle)
+      },
+    })
+    report(result)
+    await expect(page.locator(`[data-slot="titlebar-tabs"] a[href="${href}"]`)).toContainText(
+      fixture.expected.targetTitle,
+    )
+  })
+
+  benchmark("stages the review body after cold session content", async ({ page, report }) => {
+    await setup(page, [])
+    await page.goto("/")
+    const row = page.locator(homeRow).filter({ hasText: fixture.expected.targetTitle }).first()
+    await expect(row).toBeVisible()
+    const result = await page.evaluate(
+      ({ rowSelector, title, contentSelector }) =>
+        new Promise<{ contentBeforeReview: boolean; samples: number }>((resolve) => {
+          let samples = 0
+          const sample = () => {
+            samples++
+            const content = !!document.querySelector(contentSelector)
+            const review = !!document.querySelector('[data-component="session-review"]')
+            if (content && !review) {
+              resolve({ contentBeforeReview: true, samples })
+              return
+            }
+            if (content && review) {
+              resolve({ contentBeforeReview: false, samples })
+              return
+            }
+            requestAnimationFrame(sample)
+          }
+          const target = [...document.querySelectorAll<HTMLElement>(rowSelector)].find((item) =>
+            item.textContent?.includes(title),
+          )
+          if (!target) throw new Error(`Home session row not found: ${title}`)
+          target.click()
+          requestAnimationFrame(sample)
+        }),
+      {
+        rowSelector: homeRow,
+        title: fixture.expected.targetTitle,
+        contentSelector: messageSelector(fixture.expected.targetMessageIDs.at(-1)!),
+      },
+    )
+    report(result)
+    expect(result.contentBeforeReview).toBe(true)
+    await expect(page.locator('[data-component="session-review"]')).toBeVisible()
+  })
+
+  benchmark("closes the only session tab and paints home", async ({ page, report }) => {
+    await setup(page, [fixture.sourceID])
+    const href = stressSessionHref(fixture.sourceID)
+    await page.goto(href)
+    await expectSessionTitle(page, fixture.expected.sourceTitle)
+    await waitForStableTimeline(page, fixture.expected.sourceMessageIDs.at(-1)!)
+    const tab = page.locator(`[data-slot="titlebar-tabs"] a[href="${href}"]`).first()
+    const close = tab.locator("..").locator('[data-component="icon-button-v2"]')
+    await expect(close).toBeVisible()
+    const result = await measureNavigationMilestones(page, {
+      triggerSelector: '[data-slot="titlebar-tabs"] [data-component="icon-button-v2"]',
+      milestones: {
+        home: { selector: homeShell },
+        row: { selector: homeRow },
+        tabRemoved: { selector: `[data-slot="titlebar-tabs"] a[href="${href}"]`, visible: false },
+      },
+      navigate: async () => {
+        await close.click()
+        await expect(page).toHaveURL("/")
+      },
+    })
+    report(result)
+  })
+})
+
+async function setup(page: Parameters<typeof mockStressTimeline>[0], sessionIDs: string[]) {
+  await mockStressTimeline(page)
+  await installTimelineSettings(page)
+  await installStressSessionTabs(page, { sessionIDs })
+}
+
+function messageSelector(id: string) {
+  return `[data-message-id="${id}"]`
+}

packages/app/e2e/performance/timeline/navigation-milestones.ts

@@ -0,0 +1,128 @@
+import type { Page } from "@playwright/test"
+
+export type NavigationMilestoneSample = {
+  observedAtMs: number
+  milestones: Record<string, boolean>
+}
+
+export function summarizeNavigationMilestones(samples: NavigationMilestoneSample[]) {
+  const names = Object.keys(samples[0]?.milestones ?? {})
+  const summarize = (matches: (sample: NavigationMilestoneSample) => boolean) => {
+    const first = samples.find(matches)
+    const stable = samples.findIndex(
+      (sample, index) =>
+        index + 2 < samples.length && matches(sample) && matches(samples[index + 1]!) && matches(samples[index + 2]!),
+    )
+    return {
+      firstObservedMs: first?.observedAtMs ?? null,
+      stableObservedMs: stable === -1 ? null : samples[stable + 2]!.observedAtMs,
+    }
+  }
+  return {
+    samples: samples.length,
+    milestones: Object.fromEntries(
+      names.map((name) => [name, summarize((sample) => sample.milestones[name] === true)]),
+    ),
+    all: summarize((sample) => names.every((name) => sample.milestones[name] === true)),
+  }
+}
+
+type NavigationMilestoneProbe = {
+  samples: NavigationMilestoneSample[]
+  stop: () => void
+}
+
+export async function measureNavigationMilestones(
+  page: Page,
+  input: {
+    triggerSelector: string
+    milestones: Record<string, { selector: string; visible?: boolean }>
+    navigate: () => Promise<void>
+  },
+) {
+  await page.evaluate(
+    ({ triggerSelector, milestones }) => {
+      const samples: NavigationMilestoneSample[] = []
+      const streaks = new Map<string, number>()
+      const marked = new Set<string>()
+      let started: number | undefined
+      let running = true
+      const visible = (selector: string) =>
+        [...document.querySelectorAll<HTMLElement>(selector)].some((element) => {
+          const rect = element.getBoundingClientRect()
+          const style = getComputedStyle(element)
+          return rect.width > 0 && rect.height > 0 && style.visibility !== "hidden" && style.display !== "none"
+        })
+      const sample = () => {
+        if (!running || started === undefined) return
+        requestAnimationFrame(() => {
+          setTimeout(() => {
+            if (!running || started === undefined) return
+            const current = Object.fromEntries(
+              Object.entries(milestones).map(([name, milestone]) => [
+                name,
+                milestone.visible === false ? !document.querySelector(milestone.selector) : visible(milestone.selector),
+              ]),
+            )
+            samples.push({
+              observedAtMs: performance.now() - started,
+              milestones: current,
+            })
+            Object.entries(current).forEach(([name, value]) => {
+              if (!value) {
+                streaks.set(name, 0)
+                return
+              }
+              if (!marked.has(`${name}.first`)) {
+                performance.mark(`opencode.navigation.${name}.first`)
+                marked.add(`${name}.first`)
+              }
+              const streak = (streaks.get(name) ?? 0) + 1
+              streaks.set(name, streak)
+              if (streak === 3) performance.mark(`opencode.navigation.${name}.stable`)
+            })
+            const all = Object.values(current).every(Boolean)
+            const allStreak = all ? (streaks.get("all") ?? 0) + 1 : 0
+            streaks.set("all", allStreak)
+            if (all && !marked.has("all.first")) {
+              performance.mark("opencode.navigation.all.first")
+              marked.add("all.first")
+            }
+            if (allStreak === 3) performance.mark("opencode.navigation.all.stable")
+            sample()
+          }, 0)
+        })
+      }
+      document.addEventListener(
+        "click",
+        (event) => {
+          if (!(event.target instanceof Element) || !event.target.closest(triggerSelector)) return
+          started = performance.now()
+          performance.mark("opencode.navigation.click")
+          sample()
+        },
+        { capture: true, once: true },
+      )
+      ;(window as Window & { __navigationMilestones?: NavigationMilestoneProbe }).__navigationMilestones = {
+        samples,
+        stop: () => {
+          running = false
+        },
+      }
+    },
+    { triggerSelector: input.triggerSelector, milestones: input.milestones },
+  )
+  await input.navigate()
+  await page.waitForFunction(() => {
+    const samples = (window as Window & { __navigationMilestones?: NavigationMilestoneProbe }).__navigationMilestones
+      ?.samples
+    if (!samples || samples.length < 3) return false
+    return samples.slice(-3).every((sample) => Object.values(sample.milestones).every(Boolean))
+  })
+  const samples = await page.evaluate(() => {
+    const probe = (window as Window & { __navigationMilestones?: NavigationMilestoneProbe }).__navigationMilestones!
+    probe.stop()
+    return probe.samples
+  })
+  return { summary: summarizeNavigationMilestones(samples), samples }
+}

packages/app/e2e/performance/timeline/session-tab-flash.spec.ts

@@ -47,3 +47,21 @@ benchmark("samples cached session repaint after the click", async ({ page, repor
   report(compressCachedRepaintTrace(result))
   expect(result.samples.length).toBeGreaterThan(0)
 })
+
+benchmark("prefetches every open session tab", async ({ page, report }) => {
+  const prefetched = new Set<string>()
+  await mockStressTimeline(page, {
+    onMessages: (input) => {
+      if (!input.before && input.phase === "start") prefetched.add(input.sessionID)
+    },
+  })
+  await installStressSessionTabs(page, {
+    sessionIDs: [fixture.sourceID, fixture.targetID, fixture.childID],
+  })
+  await installTimelineSettings(page)
+  await page.goto(stressSessionHref(fixture.sourceID))
+  await expectSessionTitle(page, fixture.expected.sourceTitle)
+
+  await expect.poll(() => prefetched.has(fixture.childID)).toBe(true)
+  report({ prefetched: [...prefetched] })
+})

packages/app/e2e/performance/timeline/session-tab-switch-benchmark.spec.ts

@@ -2,7 +2,13 @@ import type { Page } from "@playwright/test"
 import { expectSessionTitle } from "../../utils/waits"
 import { benchmark, expect, withBenchmarkPage } from "../benchmark"
 import { fixture } from "./session-timeline-stress.fixture"
-import { installStressSessionTabs, mockStressTimeline, stressSessionHref } from "./timeline-test-helpers"
+import {
+  createReviewDiffs,
+  installStressSessionTabs,
+  installTimelineSettings,
+  mockStressTimeline,
+  stressSessionHref,
+} from "./timeline-test-helpers"
 import { measureSessionSwitch, waitForStableTimeline } from "./session-tab-switch-probe"
 
 type Result = Awaited<ReturnType<typeof measureSessionSwitch>>
@@ -20,8 +26,41 @@ benchmark("benchmarks cold and hot session tab switching", async ({ browser, rep
   report({ results, summary: summarize(results) })
 })
 
-async function trial(page: Page, mode: "cold" | "hot") {
-  await mockStressTimeline(page)
+benchmark(
+  "benchmarks v2 session tab switching with and without the review pane",
+  async ({ browser, report }, testInfo) => {
+    benchmark.setTimeout(360_000)
+    const runs = Number(process.env.SESSION_TAB_SWITCH_RUNS ?? 5)
+    const results = {
+      closed: { cold: [] as Result[], hot: [] as Result[] },
+      open: { cold: [] as Result[], hot: [] as Result[] },
+    }
+    for (const reviewPane of ["closed", "open"] as const) {
+      for (const mode of ["cold", "hot"] as const) {
+        for (let run = 0; run < runs; run++) {
+          results[reviewPane][mode].push(
+            await withBenchmarkPage(
+              browser,
+              `session-tab-switch-v2-${reviewPane}-${mode}-${run}`,
+              (page) => trial(page, mode, { newLayoutDesigns: true, reviewPane }),
+              testInfo,
+            ),
+          )
+        }
+      }
+    }
+    report({ results, summary: summarizeReviewPane(results) }, { runs, reviewDiffs: createReviewDiffs().length })
+  },
+)
+
+async function trial(
+  page: Page,
+  mode: "cold" | "hot",
+  options?: { newLayoutDesigns?: boolean; reviewPane?: "closed" | "open" },
+) {
+  const reviewDiffs = options?.newLayoutDesigns ? createReviewDiffs() : undefined
+  await mockStressTimeline(page, { vcsDiff: reviewDiffs })
+  if (options?.newLayoutDesigns) await installTimelineSettings(page)
   await installStressSessionTabs(page)
   if (mode === "hot") {
     await page.goto(stressSessionHref(fixture.targetID))
@@ -33,6 +72,10 @@ async function trial(page: Page, mode: "cold" | "hot") {
     await expectSessionTitle(page, fixture.expected.sourceTitle)
   }
   await waitForStableTimeline(page, fixture.expected.sourceMessageIDs.at(-1)!)
+  if (options?.reviewPane === "open") {
+    await openReviewPane(page)
+    await waitForStableTimeline(page, fixture.expected.sourceMessageIDs.at(-1)!)
+  }
 
   const destinationIDs = fixture.messages[fixture.targetID].map((message) => message.info.id)
   const sourceIDs = fixture.messages[fixture.sourceID].map((message) => message.info.id)
@@ -70,6 +113,15 @@ function summarize(results: Record<"cold" | "hot", Result[]>) {
   )
 }
 
+function summarizeReviewPane(results: Record<"closed" | "open", Record<"cold" | "hot", Result[]>>) {
+  return Object.fromEntries(
+    Object.entries(results).map(([reviewPane, values]) => [
+      reviewPane,
+      summarize(values as Record<"cold" | "hot", Result[]>),
+    ]),
+  )
+}
+
 async function switchSession(page: Page, sessionID: string, title: string) {
   const href = stressSessionHref(sessionID)
   const tab = page.locator(`[data-slot="titlebar-tabs"] a[href="${href}"]`).first()
@@ -77,3 +129,16 @@ async function switchSession(page: Page, sessionID: string, title: string) {
   await tab.click()
   await expectSessionTitle(page, title)
 }
+
+async function openReviewPane(page: Page) {
+  await page.getByRole("button", { name: "Toggle review" }).click()
+  const panel = page.locator("#review-panel")
+  await expect(panel).toBeVisible()
+  // Text-based readiness works across review implementations; the legacy list mounts
+  // diff viewers lazily while V2 mounts the active preview eagerly.
+  await page.waitForFunction(() => {
+    const panel = document.querySelector<HTMLElement>("#review-panel")
+    const text = panel?.textContent ?? ""
+    return text.includes("generated-000.ts") && text.includes("+3")
+  })
+}

packages/app/e2e/performance/timeline/session-tab-switch-metrics.ts

@@ -5,6 +5,12 @@ export type SessionSwitchSample = {
   hasVisibleRows: boolean
   last: boolean
   bottomErrorPx?: number
+  review?: {
+    fileHost: boolean
+    fileHostReplaced: boolean
+    header: string
+    replacedLevels: string[]
+  }
 }
 
 export function classifySessionSwitch(samples: SessionSwitchSample[]) {
@@ -23,6 +29,10 @@ export function classifySessionSwitch(samples: SessionSwitchSample[]) {
       (sample) => sample.hasVisibleRows && sample.destination.length === 0 && sample.source.length === 0,
     ).length,
     sourceSamples: samples.filter((sample) => sample.source.length > 0).length,
+    reviewFileHostMissingSamples: samples.filter((sample) => sample.review && !sample.review.fileHost).length,
+    reviewFileHostReplacedSamples: samples.filter((sample) => sample.review?.fileHostReplaced).length,
+    reviewHeaders: [...new Set(samples.flatMap((sample) => (sample.review ? [sample.review.header] : [])))],
+    reviewReplacedLevels: [...new Set(samples.flatMap((sample) => sample.review?.replacedLevels ?? []))],
   }
 }
 

packages/app/e2e/performance/timeline/session-tab-switch-probe.ts

@@ -16,11 +16,41 @@ async function installSessionSwitchProbe(
     const samples: SessionSwitchSample[] = []
     let started: number | undefined
     let running = true
+    const reviewLevels: Record<string, string> = {
+      panel: "#review-panel",
+      tabs: '#review-panel [data-component="tabs"]',
+      body: '#review-panel [data-slot="session-review-v2-body"]',
+      review: '#review-panel [data-component="session-review-v2"]',
+      preview: '#review-panel [data-slot="session-review-v2-preview"]',
+      scroll: '#review-panel [data-slot="session-review-v2-diff-scroll"]',
+      file: '#review-panel [data-component="file"][data-mode="diff"]',
+    }
+    const initialReviewNodes: Record<string, Element | null> = {}
     const sample = () => {
       if (!running || started === undefined) return
       setTimeout(() => {
         if (!running || started === undefined) return
         const observedAtMs = performance.now() - started
+        const reviewPanel = document.querySelector<HTMLElement>("#review-panel")
+        const reviewFile = reviewPanel?.querySelector('[data-component="file"][data-mode="diff"]')
+        const initialReviewFile = initialReviewNodes.file
+        const replacedLevels = Object.entries(reviewLevels).flatMap(([name, selector]) => {
+          const initial = initialReviewNodes[name]
+          if (!initial) return []
+          const current = document.querySelector(selector)
+          return current && current !== initial ? [name] : []
+        })
+        const review = reviewPanel
+          ? {
+              fileHost: !!reviewFile,
+              fileHostReplaced: !!initialReviewFile && !!reviewFile && reviewFile !== initialReviewFile,
+              header:
+                reviewPanel
+                  .querySelector<HTMLElement>('[data-slot="session-review-v2-file-header"]')
+                  ?.textContent?.trim() ?? "",
+              replacedLevels,
+            }
+          : undefined
         const root = [...document.querySelectorAll<HTMLElement>(".scroll-view__viewport")].find((element) =>
           element.querySelector("[data-timeline-row]"),
         )
@@ -44,9 +74,10 @@ async function installSessionSwitchProbe(
             hasVisibleRows,
             last: visible.includes(lastID),
             bottomErrorPx: spacer ? spacer.bottom - view.bottom : undefined,
+            review,
           })
         } else {
-          samples.push({ observedAtMs, destination: [], source: [], hasVisibleRows: false, last: false })
+          samples.push({ observedAtMs, destination: [], source: [], hasVisibleRows: false, last: false, review })
         }
         requestAnimationFrame(sample)
       }, 0)
@@ -57,6 +88,9 @@ async function installSessionSwitchProbe(
         const link = event.target instanceof Element ? event.target.closest("a") : undefined
         if (link?.getAttribute("href") !== href) return
         started = performance.now()
+        for (const [name, selector] of Object.entries(reviewLevels)) {
+          initialReviewNodes[name] = document.querySelector(selector)
+        }
         requestAnimationFrame(sample)
       },
       { capture: true, once: true },

packages/app/e2e/performance/timeline/session-timeline-benchmark.fixture.ts

@@ -93,37 +93,53 @@ const assistantMessage = {
   parts: [editPart],
 }
 
-export async function setupTimelineBenchmark(page: Page, options: { historyTurns: number; eventBatch: number }) {
+export async function setupTimelineBenchmark(
+  page: Page,
+  options: {
+    historyTurns: number
+    eventBatch: number
+    newLayoutDesigns?: boolean
+    vcsDiff?: unknown[]
+    turnDiffs?: unknown[]
+  },
+) {
   const events: EventPayload[] = []
   let eventBatch = options.eventBatch
+  const currentUserMessage = options.turnDiffs
+    ? { ...userMessage, info: { ...userMessage.info, summary: { diffs: options.turnDiffs } } }
+    : userMessage
   await mockOpenCodeServer(page, {
     directory,
     project: project(),
     provider: provider(),
     sessions: [session()],
+    vcsDiff: options.vcsDiff,
     pageMessages: () => ({
       items: [
         ...Array.from({ length: options.historyTurns }, (_, index) => performanceTurn(index)).flat(),
-        userMessage,
+        currentUserMessage,
         assistantMessage,
       ],
     }),
     events: () => events.splice(0, eventBatch),
     eventRetry: 16,
   })
-  await page.addInitScript(() => {
-    localStorage.setItem(
-      "settings.v3",
-      JSON.stringify({
-        general: {
-          editToolPartsExpanded: true,
-          shellToolPartsExpanded: true,
-          showReasoningSummaries: true,
-          showSessionProgressBar: true,
-        },
-      }),
-    )
-  })
+  await page.addInitScript(
+    (input) => {
+      localStorage.setItem(
+        "settings.v3",
+        JSON.stringify({
+          general: {
+            newLayoutDesigns: input.newLayoutDesigns,
+            editToolPartsExpanded: true,
+            shellToolPartsExpanded: true,
+            showReasoningSummaries: true,
+          },
+        }),
+      )
+    },
+    { newLayoutDesigns: options.newLayoutDesigns ?? false },
+  )
   await page.setViewportSize({ width: 1366, height: 768 })
   const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
   const text = page.locator(`[data-timeline-part-id="${textPartID}"]`).first()

packages/app/e2e/performance/timeline/session-timeline-benchmark.spec.ts

@@ -1,3 +1,4 @@
+import type { Page } from "@playwright/test"
 import { benchmark, benchmarkDiagnostics, expect } from "../benchmark"
 import {
   buildInitialStreamEvent,
@@ -6,80 +7,300 @@ import {
   textPartID,
 } from "./session-timeline-benchmark.fixture"
 import { startTimelineProfile } from "./session-timeline-profile"
+import { createReviewDiffs } from "./timeline-test-helpers"
 import {
   collectTimelineStreamMetrics,
   installTimelineStreamProbe,
   startTimelineStreamProbe,
 } from "./session-timeline-stream-probe"
 
+type TimelineStreamOptions = {
+  newLayoutDesigns?: boolean
+  reviewDiffs?: boolean
+  reviewPane?: boolean
+}
+
+type ReviewPaneSample = {
+  observedAtMs: number
+  panelVisible: boolean
+  header: string
+  diffViewers: number
+  diffLines: number
+  codeBlocks: number
+  ready: boolean
+}
+
+type ReviewPaneProbe = {
+  samples: ReviewPaneSample[]
+  start: () => void
+  stop: () => void
+}
+
+const reviewReadyStreak = 3
+
 benchmark.describe("performance: session timeline streaming", () => {
   benchmark("streams assistant text without remounting or oscillating", async ({ page, report }) => {
-    benchmark.setTimeout(480_000)
-    const cpuThrottle = Number(process.env.TIMELINE_CPU_THROTTLE ?? 30)
-    const deltaCount = Number(process.env.TIMELINE_DELTA_COUNT ?? 160)
-    const historyTurns = Number(process.env.TIMELINE_HISTORY_TURNS ?? 320)
-    const eventBatch = Number(process.env.TIMELINE_EVENT_BATCH ?? 1)
-    const minimal = process.env.TIMELINE_MINIMAL === "1"
-    const profileCPU = process.env.TIMELINE_CPU_PROFILE === "1"
-    const profileVisual = !minimal && profileCPU && process.env.TIMELINE_VISUAL_PROFILE !== "0"
+    benchmark.setTimeout(Number(process.env.TIMELINE_COMPLETION_TIMEOUT_MS ?? 420_000) + 60_000)
+    const result = await runTimelineStreamBenchmark(page, {})
+    report(result.metrics, result.context)
+  })
+
+  benchmark("streams assistant text in v2 with review pane closed", async ({ page, report }) => {
+    benchmark.setTimeout(Number(process.env.TIMELINE_COMPLETION_TIMEOUT_MS ?? 420_000) + 60_000)
+    const result = await runTimelineStreamBenchmark(page, { newLayoutDesigns: true })
+    report(result.metrics, result.context)
+  })
+
+  benchmark("streams assistant text in v2 with review diffs and pane closed", async ({ page, report }) => {
+    benchmark.setTimeout(Number(process.env.TIMELINE_COMPLETION_TIMEOUT_MS ?? 420_000) + 60_000)
+    const result = await runTimelineStreamBenchmark(page, { newLayoutDesigns: true, reviewDiffs: true })
+    report(result.metrics, result.context)
+  })
+
+  benchmark("streams assistant text in v2 with review pane open", async ({ page, report }) => {
+    benchmark.setTimeout(Number(process.env.TIMELINE_COMPLETION_TIMEOUT_MS ?? 420_000) + 60_000)
+    const result = await runTimelineStreamBenchmark(page, { newLayoutDesigns: true, reviewPane: true })
+    report(result.metrics, result.context)
+  })
+})
+
+benchmark.describe("performance: review pane", () => {
+  benchmark("loads v2 review diffs and switches active files", async ({ page, report }) => {
+    benchmark.setTimeout(240_000)
+    const historyTurns = Number(process.env.REVIEW_PANE_HISTORY_TURNS ?? 72)
+    const diffs = createReviewDiffs()
     const fixture = await setupTimelineBenchmark(page, {
       historyTurns,
-      eventBatch,
+      eventBatch: 1,
+      newLayoutDesigns: true,
+      vcsDiff: diffs,
     })
 
-    fixture.transport.enqueue(buildInitialStreamEvent(deltaCount))
-    const contentStart = performance.now()
+    fixture.transport.enqueue(buildInitialStreamEvent(1))
     await expect(fixture.text).toBeVisible()
     await expect(fixture.text).toContainText("Implementation plan")
-    const initialContentObservedMs = performance.now() - contentStart
     await fixture.scrollToBottom()
     await fixture.waitForStableGeometry()
 
-    const profile = await startTimelineProfile(page, { cpuThrottle, profileCPU })
-    await installTimelineStreamProbe(page, { textPartID, finalIndex: deltaCount, profileVisual, minimal })
-    const deltas = buildStreamDeltaEvents(deltaCount)
-    await startTimelineStreamProbe(page)
-    fixture.transport.enqueue(deltas)
-
-    await page.waitForFunction(
-      (finalIndex) =>
-        (
-          window as Window & {
-            __timelineStreamBenchmark?: { applied: { index: number }[] }
-          }
-        ).__timelineStreamBenchmark?.applied.some((value) => value.index === finalIndex),
-      deltaCount,
-      { timeout: 420_000 },
-    )
-    await expect(fixture.text).toContainText("benchmark-complete")
-    await expect(fixture.text).toContainText("Streaming")
-    await fixture.waitForStableGeometry()
-    const metrics = await collectTimelineStreamMetrics(page, {
-      textPartID,
-      finalIndex: deltaCount,
-      navigations: benchmarkDiagnostics(page).navigations,
-    })
-    const delivered = deltas.length - fixture.transport.pendingCount()
-    await profile.stop()
+    const open = await measureReviewPaneLoad(page, diffs[0]!.file)
+    const switches = []
+    for (const diff of diffs.slice(1, 4)) switches.push(await measureReviewNextFile(page, diff.file))
 
     report(
       {
-        endToEndInitialContentObservedMs: initialContentObservedMs,
-        ...metrics,
-        deliveredDeltas: delivered,
-        pendingDeltas: fixture.transport.pendingCount(),
+        open,
+        switches,
       },
       {
-        cpuThrottle,
-        profileCPU,
-        profileVisual,
-        minimal,
-        queuedDeltas: deltas.length,
         historyTurns,
-        eventBatch,
+        reviewDiffs: diffs.length,
       },
     )
-
-    await profile.reset()
   })
 })
+
+async function runTimelineStreamBenchmark(page: Page, options: TimelineStreamOptions) {
+  const completionTimeoutMs = Number(process.env.TIMELINE_COMPLETION_TIMEOUT_MS ?? 420_000)
+  const cpuThrottle = Number(process.env.TIMELINE_CPU_THROTTLE ?? 30)
+  const deltaCount = Number(process.env.TIMELINE_DELTA_COUNT ?? 160)
+  const historyTurns = Number(process.env.TIMELINE_HISTORY_TURNS ?? 320)
+  const eventBatch = Number(process.env.TIMELINE_EVENT_BATCH ?? 1)
+  const minimal = process.env.TIMELINE_MINIMAL === "1"
+  const profileCPU = process.env.TIMELINE_CPU_PROFILE === "1"
+  const profileVisual = !minimal && profileCPU && process.env.TIMELINE_VISUAL_PROFILE !== "0"
+  const diffs = options.reviewDiffs || options.reviewPane ? createReviewDiffs() : undefined
+  const fixture = await setupTimelineBenchmark(page, {
+    historyTurns,
+    eventBatch,
+    newLayoutDesigns: options.newLayoutDesigns,
+    // Turn diffs exercise timeline data cost; the pane-open scenario serves the same
+    // diffs through the default git mode so it works across review implementations.
+    turnDiffs: options.reviewDiffs ? diffs : undefined,
+    vcsDiff: options.reviewPane ? diffs : undefined,
+  })
+
+  fixture.transport.enqueue(buildInitialStreamEvent(deltaCount))
+  const contentStart = performance.now()
+  await expect(fixture.text).toBeVisible()
+  await expect(fixture.text).toContainText("Implementation plan")
+  const initialContentObservedMs = performance.now() - contentStart
+  await fixture.scrollToBottom()
+  await fixture.waitForStableGeometry()
+
+  const reviewPane = options.reviewPane && diffs ? await measureReviewPaneLoad(page, diffs[0]!.file) : undefined
+  if (reviewPane) await fixture.waitForStableGeometry()
+
+  const profile = await startTimelineProfile(page, { cpuThrottle, profileCPU })
+  await installTimelineStreamProbe(page, { textPartID, finalIndex: deltaCount, profileVisual, minimal })
+  const deltas = buildStreamDeltaEvents(deltaCount)
+  await startTimelineStreamProbe(page)
+  fixture.transport.enqueue(deltas)
+
+  await page.waitForFunction(
+    (finalIndex) =>
+      (
+        window as Window & {
+          __timelineStreamBenchmark?: { applied: { index: number }[] }
+        }
+      ).__timelineStreamBenchmark?.applied.some((value) => value.index === finalIndex),
+    deltaCount,
+    { timeout: completionTimeoutMs },
+  )
+  await expect(fixture.text).toContainText("benchmark-complete")
+  await expect(fixture.text).toContainText("Streaming")
+  await fixture.waitForStableGeometry()
+  const metrics = await collectTimelineStreamMetrics(page, {
+    textPartID,
+    finalIndex: deltaCount,
+    navigations: benchmarkDiagnostics(page).navigations,
+  })
+  const delivered = deltas.length - fixture.transport.pendingCount()
+  await profile.stop()
+
+  const result = {
+    metrics: {
+      endToEndInitialContentObservedMs: initialContentObservedMs,
+      ...metrics,
+      deliveredDeltas: delivered,
+      pendingDeltas: fixture.transport.pendingCount(),
+      reviewPane: reviewPane ?? null,
+    },
+    context: {
+      cpuThrottle,
+      profileCPU,
+      profileVisual,
+      minimal,
+      queuedDeltas: deltas.length,
+      historyTurns,
+      eventBatch,
+      newLayoutDesigns: options.newLayoutDesigns === true,
+      reviewPane: options.reviewPane === true ? "open" : "closed",
+      reviewDiffs: diffs?.length ?? 0,
+    },
+  }
+
+  await profile.reset()
+  return result
+}
+
+async function measureReviewPaneLoad(page: Page, file: string) {
+  // Default git mode reads the mocked /vcs/diff data, so opening the pane is enough
+  // and the flow works across review pane implementations.
+  await installReviewPaneProbe(page, { file })
+  await startReviewPaneProbe(page)
+  await page.getByRole("button", { name: "Toggle review" }).click()
+  await expect(page.locator("#review-panel")).toBeVisible()
+  return collectReviewPaneProbe(page)
+}
+
+async function measureReviewNextFile(page: Page, file: string) {
+  await installReviewPaneProbe(page, { file })
+  await startReviewPaneProbe(page)
+  await page.getByRole("button", { name: "Next file" }).click()
+  return collectReviewPaneProbe(page)
+}
+
+async function installReviewPaneProbe(page: Page, input: { file: string }) {
+  await page.evaluate((input) => {
+    const samples: ReviewPaneSample[] = []
+    const basename = input.file.split(/[\\/]/).at(-1) ?? input.file
+    let started: number | undefined
+    let running = true
+
+    const paneState = () => {
+      const panel = document.querySelector<HTMLElement>("#review-panel")
+      const review = panel?.querySelector<HTMLElement>('[data-component="session-review-v2"]')
+      const rect = (review ?? panel)?.getBoundingClientRect()
+      const text = panel?.textContent ?? ""
+      const previewHeader = panel?.querySelector<HTMLElement>(
+        '[data-slot="session-review-v2-file-header"]',
+      )?.textContent
+      const header = previewHeader ?? text
+      const viewers = panel ? [...panel.querySelectorAll<HTMLElement>('[data-component="file"][data-mode="diff"]')] : []
+      const codeBlocks = panel?.querySelectorAll("code").length ?? 0
+      const diffLines = viewers.reduce(
+        (sum, viewer) =>
+          sum +
+          (viewer.shadowRoot?.querySelectorAll("[data-line]").length ?? viewer.querySelectorAll("[data-line]").length),
+        0,
+      )
+      const panelVisible =
+        !!panel && panel.getAttribute("aria-hidden") !== "true" && !!rect && rect.width > 0 && rect.height > 0
+      return {
+        panelVisible,
+        header: header.slice(0, 500),
+        diffViewers: viewers.length,
+        diffLines,
+        codeBlocks,
+        ready:
+          panelVisible &&
+          header.includes(basename) &&
+          (viewers.length > 0 || text.includes("+3") || diffLines > 0 || codeBlocks > 0),
+      }
+    }
+
+    const sample = () => {
+      if (!running || started === undefined) return
+      requestAnimationFrame(() => {
+        setTimeout(() => {
+          if (!running || started === undefined) return
+          samples.push({ observedAtMs: performance.now() - started, ...paneState() })
+          if (performance.now() - started < 10_000) sample()
+        }, 0)
+      })
+    }
+
+    ;(window as Window & { __reviewPaneProbe?: ReviewPaneProbe }).__reviewPaneProbe = {
+      samples,
+      start: () => {
+        started = performance.now()
+        performance.mark("opencode.review-pane.click")
+        sample()
+      },
+      stop: () => {
+        running = false
+      },
+    }
+  }, input)
+}
+
+async function startReviewPaneProbe(page: Page) {
+  await page.evaluate(() => {
+    ;(window as Window & { __reviewPaneProbe?: ReviewPaneProbe }).__reviewPaneProbe!.start()
+  })
+}
+
+async function collectReviewPaneProbe(page: Page) {
+  await page.waitForFunction((streak) => {
+    const samples = (window as Window & { __reviewPaneProbe?: ReviewPaneProbe }).__reviewPaneProbe?.samples
+    if (!samples) return false
+    return samples.some((_, index) => {
+      const stable = samples.slice(index, index + streak)
+      return stable.length === streak && stable.every((sample) => sample.ready)
+    })
+  }, reviewReadyStreak)
+
+  const samples = await page.evaluate(() => {
+    const probe = (window as Window & { __reviewPaneProbe?: ReviewPaneProbe }).__reviewPaneProbe!
+    probe.stop()
+    return probe.samples
+  })
+  return { summary: summarizeReviewPaneSamples(samples), samples }
+}
+
+function summarizeReviewPaneSamples(samples: ReviewPaneSample[]) {
+  const firstReady = samples.find((sample) => sample.ready)
+  const stableIndex = samples.findIndex((_, index) => {
+    const stable = samples.slice(index, index + reviewReadyStreak)
+    return stable.length === reviewReadyStreak && stable.every((sample) => sample.ready)
+  })
+  return {
+    samples: samples.length,
+    firstReadyObservedMs: firstReady?.observedAtMs ?? null,
+    stableReadyObservedMs: stableIndex === -1 ? null : samples[stableIndex + reviewReadyStreak - 1]!.observedAtMs,
+    notReadySamples: samples.filter((sample) => !sample.ready).length,
+    maxDiffViewers: Math.max(0, ...samples.map((sample) => sample.diffViewers)),
+    maxDiffLines: Math.max(0, ...samples.map((sample) => sample.diffLines)),
+    maxCodeBlocks: Math.max(0, ...samples.map((sample) => sample.codeBlocks)),
+  }
+}

packages/app/e2e/performance/timeline/session-timeline-stress.fixture.ts

@@ -23,6 +23,7 @@ const words = [
 
 const sourceID = "ses_smoke_source"
 const targetID = "ses_smoke_target"
+const childID = "ses_smoke_child"
 const directory = "C:/OpenCode/SmokeProject"
 const projectID = "proj_smoke_timeline"
 const model = { providerID: "opencode", modelID: "claude-opus-4-6", variant: "max" }
@@ -126,9 +127,11 @@ function toolPart(
   tool: string,
   input: Record<string, unknown>,
   outputLength = 160,
+  metadataOverride?: Record<string, unknown>,
 ): MessagePart {
   const metadata =
-    tool === "apply_patch"
+    metadataOverride ??
+    (tool === "apply_patch"
       ? { files: [patchFile(index, "update"), patchFile(index + 1, index % 2 === 0 ? "add" : "delete")] }
       : tool === "edit" || tool === "write"
         ? {
@@ -138,7 +141,7 @@ function toolPart(
           }
         : tool === "question"
           ? { answers: [["Proceed"], ["Keep sample output"]] }
-          : {}
+          : {})
   return {
     id: id(`prt_tool_${tool}_${partIndex}`, index),
     type: "tool",
@@ -244,7 +247,25 @@ function turn(index: number): Message[] {
 const targetMessages = Array.from({ length: 72 }, (_, index) => turn(index)).flat()
 const sourceMessages = Array.from({ length: 12 }, (_, index) => [
   userMessage(sourceID, index + 1000, 120),
-  assistantMessage(sourceID, index + 1000, id("msg_user", index + 1000), [textPart(index + 1000, 0, 240)]),
+  assistantMessage(sourceID, index + 1000, id("msg_user", index + 1000), [
+    textPart(index + 1000, 0, 240),
+    ...(index === 11
+      ? [
+          toolPart(
+            index + 1000,
+            1,
+            "task",
+            { description: "Inspect child navigation", subagent_type: "explore" },
+            160,
+            { sessionId: childID },
+          ),
+        ]
+      : []),
+  ]),
+]).flat()
+const childMessages = Array.from({ length: 4 }, (_, index) => [
+  userMessage(childID, index + 2000, 120),
+  assistantMessage(childID, index + 2000, id("msg_user", index + 2000), [textPart(index + 2000, 0, 240)]),
 ]).flat()
 
 function renderable(part: MessagePart) {
@@ -298,19 +319,32 @@ export const fixture = {
       version: "dev",
       time: { created: 1700000001000, updated: 1700000001000 },
     },
+    {
+      id: childID,
+      parentID: sourceID,
+      slug: "child",
+      projectID,
+      directory,
+      title: "Inspect child navigation",
+      version: "dev",
+      time: { created: 1700000002000, updated: 1700000002000 },
+    },
   ],
   sourceID,
   targetID,
-  messages: { [sourceID]: sourceMessages, [targetID]: targetMessages },
+  childID,
+  messages: { [sourceID]: sourceMessages, [targetID]: targetMessages, [childID]: childMessages },
   expected: {
     sourceTitle: "Uncommitted changes inquiry",
     targetTitle: "Example Game: sample jump movement & sample physics analysis",
+    childTitle: "Inspect child navigation",
     sourceMessageIDs: sourceMessages
       .filter((message) => message.info.role === "user")
       .map((message) => message.info.id),
     targetMessageIDs: targetMessages
       .filter((message) => message.info.role === "user")
       .map((message) => message.info.id),
+    childMessageIDs: childMessages.filter((message) => message.info.role === "user").map((message) => message.info.id),
     targetPartIDs: targetMessages.flatMap((message) =>
       orderedParts(message)
         .filter(renderable)

packages/app/e2e/performance/timeline/timeline-test-helpers.ts

@@ -1,7 +1,7 @@
 import type { Page } from "@playwright/test"
 import { base64Encode } from "@opencode-ai/core/util/encode"
 import { mockOpenCodeServer } from "../../utils/mock-server"
-import { fixture } from "./session-timeline-stress.fixture"
+import { fixture, pageMessages } from "./session-timeline-stress.fixture"
 
 export async function installTimelineSettings(page: Page) {
   await page.addInitScript(() => {
@@ -9,30 +9,38 @@ export async function installTimelineSettings(page: Page) {
       "settings.v3",
       JSON.stringify({
         general: {
+          newLayoutDesigns: true,
           editToolPartsExpanded: true,
           shellToolPartsExpanded: true,
           showReasoningSummaries: true,
-          showSessionProgressBar: true,
         },
       }),
     )
   })
 }
 
-export function mockStressTimeline(page: Page) {
+export function mockStressTimeline(
+  page: Page,
+  input?: {
+    onMessages?: (input: { sessionID: string; before?: string; phase: "start" | "end" }) => void
+    vcsDiff?: unknown[]
+  },
+) {
   return mockOpenCodeServer(page, {
     sessions: fixture.sessions,
     provider: fixture.provider,
     directory: fixture.directory,
     project: fixture.project,
-    pageMessages: (sessionID) => ({ items: fixture.messages[sessionID as keyof typeof fixture.messages] ?? [] }),
+    pageMessages,
+    onMessages: input?.onMessages,
+    vcsDiff: input?.vcsDiff,
   })
 }
 
-export async function installStressSessionTabs(page: Page) {
-  const server = `http://${process.env.PLAYWRIGHT_SERVER_HOST ?? "127.0.0.1"}:${process.env.PLAYWRIGHT_SERVER_PORT ?? "4096"}`
+export async function installStressSessionTabs(page: Page, input?: { draftID?: string; sessionIDs?: string[] }) {
+  const server = stressServer()
   await page.addInitScript(
-    ({ directory, sourceID, targetID, dirBase64, server }) => {
+    ({ directory, sessionIDs, dirBase64, server, draftID }) => {
       localStorage.setItem(
         "opencode.global.dat:server",
         JSON.stringify({
@@ -41,27 +49,86 @@ export async function installStressSessionTabs(page: Page) {
         }),
       )
       localStorage.setItem(
-        "opencode.global.dat:tabs",
-        JSON.stringify(
-          [sourceID, targetID].map((sessionId) => ({
+        "opencode.window.browser.dat:tabs",
+        JSON.stringify([
+          ...sessionIDs.map((sessionId) => ({
             type: "session",
             server,
             dirBase64,
             sessionId,
           })),
-        ),
+          ...(draftID ? [{ type: "draft", draftID, server, directory }] : []),
+        ]),
       )
     },
     {
       directory: fixture.directory,
-      sourceID: fixture.sourceID,
-      targetID: fixture.targetID,
+      sessionIDs: input?.sessionIDs ?? [fixture.sourceID, fixture.targetID],
       dirBase64: base64Encode(fixture.directory),
       server,
+      draftID: input?.draftID,
     },
   )
 }
 
 export function stressSessionHref(sessionID: string) {
-  return `/${base64Encode(fixture.directory)}/session/${sessionID}`
+  return `/server/${base64Encode(stressServer())}/session/${sessionID}`
+}
+
+export function stressDraftHref(draftID: string) {
+  return `/new-session?draftId=${encodeURIComponent(draftID)}`
+}
+
+function stressServer() {
+  return `http://${process.env.PLAYWRIGHT_SERVER_HOST ?? "127.0.0.1"}:${process.env.PLAYWRIGHT_SERVER_PORT ?? "4096"}`
+}
+
+export function createReviewDiffs() {
+  return Array.from({ length: Number(process.env.REVIEW_PANE_DIFF_COUNT ?? 72) }, (_, index) => {
+    const lines = index % 3 === 0 ? 300 : index % 3 === 1 ? 120 : 38
+    const file = `src/review/generated-${String(index).padStart(3, "0")}.ts`
+    const before = reviewSource(index, lines)
+    const after = before
+      .replace(`value_${index}_4`, `updated_${index}_4`)
+      .replace(
+        `value_${index}_${Math.max(8, Math.floor(lines / 2))}`,
+        `updated_${index}_${Math.max(8, Math.floor(lines / 2))}`,
+      )
+      .replace(`value_${index}_${lines - 4}`, `updated_${index}_${lines - 4}`)
+    return {
+      file,
+      patch: reviewPatch(file, before, after),
+      additions: 3,
+      deletions: 3,
+      status: "modified" as const,
+    }
+  })
+}
+
+function reviewSource(seed: number, lines: number) {
+  return Array.from(
+    { length: lines },
+    (_, index) => `export const value_${seed}_${index} = "${reviewWords(seed + index, index % 5 === 0 ? 180 : 42)}"`,
+  ).join("\n")
+}
+
+function reviewPatch(file: string, before: string, after: string) {
+  const beforeLines = before.split("\n")
+  const afterLines = after.split("\n")
+  return [
+    `diff --git a/${file} b/${file}`,
+    `--- a/${file}`,
+    `+++ b/${file}`,
+    `@@ -1,${beforeLines.length} +1,${afterLines.length} @@`,
+    ...beforeLines.flatMap((line, index) => {
+      const next = afterLines[index]!
+      if (line === next) return [` ${line}`]
+      return [`-${line}`, `+${next}`]
+    }),
+  ].join("\n")
+}
+
+function reviewWords(seed: number, length: number) {
+  const words = ["alpha", "bravo", "charlie", "delta", "echo", "foxtrot", "golf", "hotel", "india", "juliet"]
+  return Array.from({ length: Math.ceil(length / 7) }, (_, index) => words[(seed + index * 3) % words.length]).join(" ")
 }

packages/app/e2e/performance/unit/first-navigation-metrics.test.ts

@@ -0,0 +1,32 @@
+import { expect, test } from "bun:test"
+import { summarizeFirstNavigation } from "../timeline/first-navigation-metrics"
+
+test("reports blank frames before first destination and stable paint", () => {
+  expect(
+    summarizeFirstNavigation([
+      { observedAtMs: 16, source: true, destination: false, content: true },
+      { observedAtMs: 32, source: false, destination: false, content: false },
+      { observedAtMs: 48, source: false, destination: true, content: true },
+      { observedAtMs: 64, source: false, destination: true, content: true },
+      { observedAtMs: 80, source: false, destination: true, content: true },
+    ]),
+  ).toEqual({
+    samples: 5,
+    firstDestinationObservedMs: 48,
+    stableDestinationObservedMs: 80,
+    sourceSamples: 1,
+    blankSamples: 1,
+    unknownSamples: 0,
+    destinationSamples: 3,
+  })
+})
+
+test("does not report stability for interrupted destination frames", () => {
+  expect(
+    summarizeFirstNavigation([
+      { observedAtMs: 16, source: false, destination: true, content: true },
+      { observedAtMs: 32, source: false, destination: false, content: true },
+      { observedAtMs: 48, source: false, destination: true, content: true },
+    ]).stableDestinationObservedMs,
+  ).toBeNull()
+})

packages/app/e2e/performance/unit/navigation-milestones.test.ts

@@ -0,0 +1,34 @@
+import { expect, test } from "bun:test"
+import { summarizeNavigationMilestones } from "../timeline/navigation-milestones"
+
+test("reports first and stable paint for each navigation milestone", () => {
+  expect(
+    summarizeNavigationMilestones([
+      { observedAtMs: 16, milestones: { content: false, tab: false } },
+      { observedAtMs: 32, milestones: { content: true, tab: false } },
+      { observedAtMs: 48, milestones: { content: true, tab: true } },
+      { observedAtMs: 64, milestones: { content: true, tab: true } },
+      { observedAtMs: 80, milestones: { content: true, tab: true } },
+    ]),
+  ).toEqual({
+    samples: 5,
+    milestones: {
+      content: { firstObservedMs: 32, stableObservedMs: 64 },
+      tab: { firstObservedMs: 48, stableObservedMs: 80 },
+    },
+    all: { firstObservedMs: 48, stableObservedMs: 80 },
+  })
+})
+
+test("reports missing stability when a milestone appears in the final samples", () => {
+  expect(
+    summarizeNavigationMilestones([
+      { observedAtMs: 16, milestones: { content: false } },
+      { observedAtMs: 32, milestones: { content: true } },
+    ]),
+  ).toEqual({
+    samples: 2,
+    milestones: { content: { firstObservedMs: 32, stableObservedMs: null } },
+    all: { firstObservedMs: 32, stableObservedMs: null },
+  })
+})

packages/app/e2e/performance/unit/timeline-test-helpers.test.ts

@@ -0,0 +1,10 @@
+import { expect, test } from "bun:test"
+import { base64Encode } from "@opencode-ai/core/util/encode"
+import { fixture } from "../timeline/session-timeline-stress.fixture"
+import { stressSessionHref } from "../timeline/timeline-test-helpers"
+
+test("builds stress session links for the benchmark server", () => {
+  expect(stressSessionHref(fixture.sourceID)).toBe(
+    `/server/${base64Encode("http://127.0.0.1:4096")}/session/${fixture.sourceID}`,
+  )
+})

packages/app/e2e/performance/unit/visual-stability.test.ts

@@ -0,0 +1,392 @@
+import { expect, test } from "bun:test"
+import {
+  analyzeVisualStability,
+  analyzeVisualStabilityByMarker,
+  type VisualStabilityTrace,
+} from "../../utils/visual-stability"
+import { analyzeVisualObservations } from "../../utils/visual-stability/analyzer"
+import { legacyVisualPlan, visualPlan, type VisualInvariant } from "../../utils/visual-stability/invariant"
+import { defineVisualRegions, mapVisualRegions } from "../../utils/visual-stability/regions"
+
+function trace(samples: VisualStabilityTrace["samples"]): VisualStabilityTrace {
+  return { markers: [], samples }
+}
+
+test("accepts continuous visible motion", () => {
+  expect(
+    analyzeVisualStability(
+      trace([
+        frame(0, region({ width: 80, bottom: 40 }), region({ top: 40, bottom: 60 })),
+        frame(16, region({ width: 75, bottom: 45 }), region({ top: 45, bottom: 65 })),
+        frame(32, region({ width: 70, bottom: 50 }), region({ top: 50, bottom: 70 })),
+      ]),
+      { flow: ["changing", "following"] },
+    ),
+  ).toEqual([])
+})
+
+test("reports repeated geometry reversals", () => {
+  const issues = analyzeVisualStability(
+    trace([
+      frame(0, region({ width: 80 })),
+      frame(16, region({ width: 60 })),
+      frame(32, region({ width: 78 })),
+      frame(48, region({ width: 62 })),
+    ]),
+  )
+
+  expect(issues.some((issue) => issue.includes("changing width reversed 2 times"))).toBe(true)
+})
+
+test("reports visible blanking, label reversal, and overlap", () => {
+  const issues = analyzeVisualStability(
+    trace([
+      frame(0, region({ label: "Exploring", opacity: 1, bottom: 40 }), region({ top: 40, bottom: 60 })),
+      frame(16, region({ label: "Explored", opacity: 0.2, bottom: 50 }), region({ top: 49, bottom: 69 })),
+      frame(32, region({ label: "Exploring", opacity: 1, bottom: 50 }), region({ top: 50, bottom: 70 })),
+    ]),
+    { flow: ["changing", "following"] },
+  )
+
+  expect(issues.some((issue) => issue.includes("opacity fell to 0.2"))).toBe(true)
+  expect(issues.some((issue) => issue.includes("label reverted"))).toBe(true)
+  expect(issues.some((issue) => issue.includes("overlapped following by 1px"))).toBe(true)
+})
+
+test("reports duplicate regions and unexpected remounts", () => {
+  const issues = analyzeVisualStability(
+    trace([frame(0, region({ node: 1 })), frame(16, region({ node: 2, count: 2 })), frame(32, region({ node: 2 }))]),
+    { stable: ["changing"], unique: ["changing"] },
+  )
+
+  expect(issues.some((issue) => issue.includes("changing appeared 2 times"))).toBe(true)
+  expect(issues.some((issue) => issue.includes("changing remounted"))).toBe(true)
+})
+
+test("reports bottom anchor loss but permits movement while scrolled away", () => {
+  const anchored = analyzeVisualStability(
+    trace([
+      { at: 0, regions: { changing: region() }, viewport: viewport(0) },
+      { at: 16, regions: { changing: region() }, viewport: viewport(24) },
+    ]),
+    { preserveBottomAnchor: true },
+  )
+  const away = analyzeVisualStability(
+    trace([
+      { at: 0, regions: { changing: region() }, viewport: viewport(80) },
+      { at: 16, regions: { changing: region() }, viewport: viewport(104) },
+    ]),
+    { preserveBottomAnchor: true },
+  )
+
+  expect(anchored.some((issue) => issue.includes("bottom anchor moved to 24px"))).toBe(true)
+  expect(away).toEqual([])
+})
+
+test("reports up down up movement while preserving a bottom anchor", () => {
+  const issues = analyzeVisualStability(
+    trace([
+      { at: 0, regions: { changing: region({ top: 200, bottom: 240 }) }, viewport: viewport(0) },
+      { at: 16, regions: { changing: region({ top: 180, bottom: 220 }) }, viewport: viewport(0) },
+      { at: 32, regions: { changing: region({ top: 196, bottom: 236 }) }, viewport: viewport(0) },
+      { at: 48, regions: { changing: region({ top: 176, bottom: 216 }) }, viewport: viewport(0) },
+    ]),
+    { preserveBottomAnchor: true, maxPositionReversals: 0 },
+  )
+
+  expect(issues.some((issue) => issue.includes("changing top reversed 2 times"))).toBe(true)
+  expect(issues.some((issue) => issue.includes("changing bottom reversed 2 times"))).toBe(true)
+})
+
+test("accepts monotonic upward movement while preserving a bottom anchor", () => {
+  expect(
+    analyzeVisualStability(
+      trace([
+        { at: 0, regions: { changing: region({ top: 200, bottom: 240 }) }, viewport: viewport(0) },
+        { at: 16, regions: { changing: region({ top: 190, bottom: 230 }) }, viewport: viewport(0) },
+        { at: 32, regions: { changing: region({ top: 180, bottom: 220 }) }, viewport: viewport(0) },
+      ]),
+      { preserveBottomAnchor: true, maxPositionReversals: 0 },
+    ),
+  ).toEqual([])
+})
+
+test("ignores overlap entirely outside the clipped timeline viewport", () => {
+  expect(
+    analyzeVisualStability(
+      trace([
+        {
+          at: 0,
+          regions: {
+            changing: region({ top: -200, bottom: -100 }),
+            following: region({ top: -150, bottom: -50 }),
+          },
+          viewport: viewport(0),
+        },
+      ]),
+      { flow: ["changing", "following"] },
+    ),
+  ).toEqual([])
+})
+
+test("reports visible anchor movement while allowing virtual scrollbar movement", () => {
+  const issues = analyzeVisualStability(
+    trace([
+      { at: 0, regions: { anchor: region({ top: 100, bottom: 120 }) }, viewport: { ...viewport(100), scrollTop: 40 } },
+      { at: 16, regions: { anchor: region({ top: 100, bottom: 120 }) }, viewport: { ...viewport(120), scrollTop: 60 } },
+    ]),
+    { fixed: ["anchor"] },
+  )
+
+  expect(issues).toEqual([])
+
+  const moved = analyzeVisualStability(
+    trace([
+      { at: 0, regions: { anchor: region({ top: 100, bottom: 120 }) }, viewport: viewport(100) },
+      { at: 16, regions: { anchor: region({ top: 112, bottom: 132 }) }, viewport: viewport(100) },
+    ]),
+    { fixed: ["anchor"] },
+  )
+  expect(moved.some((issue) => issue.includes("anchor moved 12px in the viewport"))).toBe(true)
+})
+
+test("analyzes each marked event independently", () => {
+  const input: VisualStabilityTrace = {
+    markers: [
+      { at: 10, label: "grow" },
+      { at: 40, label: "shrink" },
+    ],
+    samples: [
+      frame(0, region({ top: 100 })),
+      frame(16, region({ top: 90 })),
+      frame(32, region({ top: 80 })),
+      frame(48, region({ top: 90 })),
+      frame(64, region({ top: 100 })),
+    ],
+  }
+
+  expect(analyzeVisualStability(input, { maxPositionReversals: 0 })).toContain("changing top reversed 1 times")
+  expect(
+    analyzeVisualStabilityByMarker(input, {
+      maxPositionReversals: 0,
+      motion: ["changing"],
+      aggregateMotion: false,
+    }),
+  ).toEqual([])
+})
+
+test("reports cross-event motion reversals by default", () => {
+  const input: VisualStabilityTrace = {
+    markers: [
+      { at: 10, label: "up" },
+      { at: 40, label: "down" },
+    ],
+    samples: [
+      frame(0, region({ top: 100 })),
+      frame(16, region({ top: 90 })),
+      frame(32, region({ top: 80 })),
+      frame(48, region({ top: 90 })),
+      frame(64, region({ top: 100 })),
+    ],
+  }
+
+  expect(analyzeVisualStabilityByMarker(input, { maxPositionReversals: 0 })).toContain("changing top reversed 1 times")
+})
+
+test("reports regions rendered in the wrong flow order", () => {
+  const issues = analyzeVisualStability(
+    trace([frame(0, region({ top: 100, bottom: 120 }), region({ top: 60, bottom: 80 }))]),
+    { flow: ["changing", "following"] },
+  )
+
+  expect(issues.some((issue) => issue.includes("changing rendered after following"))).toBe(true)
+})
+
+test("uses painted bounds instead of clipped layout overflow", () => {
+  expect(
+    analyzeVisualStability(
+      trace([
+        frame(
+          0,
+          region({ top: 100, bottom: 140, height: 40, layoutTop: 100, layoutBottom: 300 }),
+          region({ top: 140, bottom: 180 }),
+        ),
+      ]),
+      { flow: ["changing", "following"] },
+    ),
+  ).toEqual([])
+})
+
+test("does not report disappearance when a present row moves outside the viewport", () => {
+  expect(
+    analyzeVisualStability(
+      trace([
+        frame(0, region({ visible: true })),
+        frame(16, region({ visible: false, inViewport: false, top: -100, bottom: -80 })),
+        frame(32, region({ visible: true })),
+      ]),
+    ),
+  ).toEqual([])
+})
+
+test("reports an in-viewport transparent frame between visible frames", () => {
+  const issues = analyzeVisualStability(
+    trace([
+      frame(0, region()),
+      frame(16, region({ visible: false, opacity: 0, inViewport: true })),
+      frame(32, region()),
+    ]),
+  )
+
+  expect(issues.some((issue) => issue.includes("blanked between visible frames"))).toBe(true)
+})
+
+test("reports an in-viewport display-none frame between visible frames", () => {
+  const issues = analyzeVisualStability(
+    trace([
+      frame(0, region()),
+      frame(16, region({ visible: false, width: 0, height: 0, inViewport: true, cssHidden: true })),
+      frame(32, region()),
+    ]),
+  )
+
+  expect(issues.some((issue) => issue.includes("blanked between visible frames"))).toBe(true)
+})
+
+test("can limit motion analysis to unaffected regions", () => {
+  expect(
+    analyzeVisualStability(
+      trace([
+        frame(0, region({ height: 20 }), region()),
+        frame(16, region({ height: 40 }), region()),
+        frame(32, region({ height: 30 }), region()),
+      ]),
+      { motion: ["following"] },
+    ),
+  ).toEqual([])
+})
+
+test("reports a blank frame across replacement surfaces", () => {
+  const issues = analyzeVisualStability(
+    {
+      markers: [],
+      samples: [
+        { at: 0, regions: { thinking: region(), error: region({ present: false, visible: false }) } },
+        {
+          at: 16,
+          regions: {
+            thinking: region({ present: false, visible: false }),
+            error: region({ present: false, visible: false }),
+          },
+        },
+        { at: 32, regions: { thinking: region({ present: false, visible: false }), error: region() } },
+      ],
+    },
+    { continuousAny: [["thinking", "error"]] },
+  )
+
+  expect(issues.some((issue) => issue.includes("thinking | error blanked"))).toBe(true)
+})
+
+test("reports failure to acquire the bottom anchor", () => {
+  const issues = analyzeVisualStability(
+    trace([
+      { at: 0, regions: { changing: region() }, viewport: viewport(600) },
+      { at: 16, regions: { changing: region() }, viewport: viewport(120) },
+    ]),
+    { acquireBottomAnchor: true },
+  )
+
+  expect(issues.some((issue) => issue.includes("did not acquire bottom anchor"))).toBe(true)
+})
+
+test("reports a required region that never renders", () => {
+  const issues = analyzeVisualStability(
+    trace([
+      {
+        at: 0,
+        regions: { changing: region({ present: false, visible: false }) },
+      },
+    ]),
+    { required: ["changing"] },
+  )
+
+  expect(issues).toContain("changing never rendered")
+})
+
+test("preserves typed region names while mapping definitions", () => {
+  const regions = defineVisualRegions({
+    changing: { selector: "[data-changing]" },
+    following: { selector: "[data-following]", closest: "[data-row]" },
+  })
+  const selectors = mapVisualRegions(regions, (region) => region.selector)
+
+  expect(selectors).toEqual({ changing: "[data-changing]", following: "[data-following]" })
+  const name: keyof typeof selectors = "changing"
+  expect(name).toBe("changing")
+})
+
+test("evaluates the typed invariant algebra over explicit observations", () => {
+  const regions = defineVisualRegions({
+    changing: { selector: "[data-changing]" },
+    following: { selector: "[data-following]" },
+  })
+  const invariants = [
+    { type: "required", regions: ["changing"] },
+    { type: "flow", regions: ["changing", "following"] },
+  ] satisfies VisualInvariant<keyof typeof regions>[]
+  // @ts-expect-error Plans reject names that are not in the region definition.
+  const invalid = { type: "required", regions: ["missing"] } satisfies VisualInvariant<keyof typeof regions>
+  const plan = visualPlan(regions, invariants, { perMarker: true })
+
+  expect(invalid.regions).toEqual(["missing"])
+  expect(plan.perMarker).toBe(true)
+  expect(analyzeVisualObservations([frame(0, region({ bottom: 50 }), region({ top: 49, bottom: 69 }))], plan)).toEqual([
+    "changing overlapped following by 1px at 0ms",
+  ])
+})
+
+test("legacy plan adapter preserves analyzer messages and order", () => {
+  const input = trace([
+    frame(0, region({ label: "Exploring", opacity: 1, bottom: 40 }), region({ top: 40, bottom: 60 })),
+    frame(16, region({ label: "Explored", opacity: 0.2, bottom: 50 }), region({ top: 49, bottom: 69 })),
+    frame(32, region({ label: "Exploring", opacity: 1, bottom: 50 }), region({ top: 50, bottom: 70 })),
+  ])
+  const options = { flow: ["changing", "following"], stable: ["changing"] }
+
+  expect(analyzeVisualObservations(input.samples, legacyVisualPlan(options))).toEqual(
+    analyzeVisualStability(input, options),
+  )
+})
+
+function frame(
+  at: number,
+  changing: VisualStabilityTrace["samples"][number]["regions"][string],
+  following?: VisualStabilityTrace["samples"][number]["regions"][string],
+) {
+  return { at, regions: { changing, ...(following ? { following } : {}) } }
+}
+
+function region(input: Partial<VisualStabilityTrace["samples"][number]["regions"][string]> = {}) {
+  return {
+    present: true,
+    visible: true,
+    inViewport: true,
+    top: 0,
+    bottom: 20,
+    width: 100,
+    height: 20,
+    opacity: 1,
+    count: 1,
+    node: 1,
+    label: "",
+    text: "",
+    layoutTop: input.top ?? 0,
+    layoutBottom: input.bottom ?? 20,
+    ...input,
+  }
+}
+
+function viewport(distanceFromBottom: number) {
+  return { top: 0, bottom: 400, scrollTop: 100, scrollHeight: 500, clientHeight: 400, distanceFromBottom }
+}

packages/app/e2e/regression/cross-server-tab-close.spec.ts

@@ -0,0 +1,135 @@
+import { expect, test, type Page, type Route } from "@playwright/test"
+import { base64Encode } from "@opencode-ai/core/util/encode"
+
+const serverA = "http://127.0.0.1:4096"
+const serverB = "http://127.0.0.1:4097"
+const sessionA = session("ses_server_a", "C:/server-a", "Server A session")
+const sessionB = session("ses_server_b", "/home/server-b", "Server B session")
+
+test("closing the active server's last tab opens the remaining server tab", async ({ page }) => {
+  const requests: string[] = []
+  await mockServers(page, requests)
+  await page.addInitScript(
+    ({ serverB, sessionA, sessionB }) => {
+      localStorage.setItem("settings.v3", JSON.stringify({ general: { newLayoutDesigns: true } }))
+      localStorage.setItem("opencode.global.dat:server", JSON.stringify({ list: [serverB] }))
+      localStorage.setItem(
+        "opencode.window.browser.dat:tabs",
+        JSON.stringify([
+          { type: "session", server: "http://127.0.0.1:4096", sessionId: sessionA },
+          { type: "session", server: serverB, sessionId: sessionB },
+        ]),
+      )
+    },
+    { serverB, sessionA: sessionA.id, sessionB: sessionB.id },
+  )
+
+  const hrefA = `/server/${base64Encode(serverA)}/session/${sessionA.id}`
+  const hrefB = `/server/${base64Encode(serverB)}/session/${sessionB.id}`
+  await page.goto(hrefA)
+  await expect(page.getByText(sessionA.title).first()).toBeVisible()
+
+  const tabA = page.locator(`[data-titlebar-tab-slot]:has(a[href="${hrefA}"])`)
+  await tabA.locator('[data-slot="tab-close"] button').click()
+
+  await expect(page).toHaveURL(new RegExp(`${hrefB.replace(/[.*+?^${}()|[\]\\]/g, "\\$&")}$`))
+  await expect.poll(() => requests.some((url) => url.startsWith(`${serverB}/session/${sessionB.id}`))).toBe(true)
+  await expect(page.getByText(sessionB.title).first()).toBeVisible()
+  const sessionBRequests = requests.filter((url) => url.includes(`/session/${sessionB.id}`))
+  expect(sessionBRequests.every((url) => url.startsWith(serverB))).toBe(true)
+  expect(
+    requests.some((request) => {
+      const url = new URL(request)
+      return url.origin === serverB && url.searchParams.get("directory") === sessionB.directory
+    }),
+  ).toBe(true)
+})
+
+test("legacy session routes preserve an existing tab's server", async ({ page }) => {
+  await mockServers(page, [])
+  await page.addInitScript(
+    ({ serverB, sessionB }) => {
+      localStorage.setItem("settings.v3", JSON.stringify({ general: { newLayoutDesigns: true } }))
+      localStorage.setItem("opencode.global.dat:server", JSON.stringify({ list: [serverB] }))
+      localStorage.setItem(
+        "opencode.window.browser.dat:tabs",
+        JSON.stringify([{ type: "session", server: serverB, sessionId: sessionB }]),
+      )
+    },
+    { serverB, sessionB: sessionB.id },
+  )
+
+  const hrefB = `/server/${base64Encode(serverB)}/session/${sessionB.id}`
+  await page.goto(`/${base64Encode(sessionB.directory)}/session/${sessionB.id}`)
+  await expect(page).toHaveURL(new RegExp(`${hrefB.replace(/[.*+?^${}()|[\]\\]/g, "\\$&")}$`))
+})
+
+function session(id: string, directory: string, title: string) {
+  return {
+    id,
+    slug: id,
+    projectID: `project-${id}`,
+    directory,
+    title,
+    version: "dev",
+    time: { created: 1, updated: 1 },
+  }
+}
+
+async function mockServers(page: Page, requests: string[]) {
+  await page.route("**/*", async (route) => {
+    const url = new URL(route.request().url())
+    if (url.origin !== serverA && url.origin !== serverB) return route.fallback()
+    requests.push(url.toString())
+    const current = url.origin === serverA ? sessionA : sessionB
+    const directory = url.searchParams.get("directory")
+    if (directory && directory !== current.directory) return json(route, { name: "InvalidDirectory" }, 500)
+    if (url.pathname === "/global/event" || url.pathname === "/event") return sse(route)
+    if (url.pathname === "/global/health") return json(route, { healthy: true })
+    if (url.pathname === "/session") return json(route, [current])
+    if (url.pathname === `/session/${current.id}`) return json(route, current)
+    if (/^\/session\/[^/]+$/.test(url.pathname)) return json(route, { name: "NotFoundError" }, 404)
+    if (url.pathname === `/session/${current.id}/message`) return json(route, [])
+    if (/^\/session\/[^/]+\/(children|todo|diff)$/.test(url.pathname)) return json(route, [])
+    if (["/skill", "/command", "/lsp", "/formatter", "/permission", "/question", "/vcs/diff"].includes(url.pathname))
+      return json(route, [])
+    if (["/global/config", "/config", "/provider/auth", "/mcp", "/session/status"].includes(url.pathname))
+      return json(route, {})
+    if (url.pathname === "/provider")
+      return json(route, { all: [], connected: [], default: { providerID: "", modelID: "" } })
+    if (url.pathname === "/agent") return json(route, [{ name: "build", mode: "primary" }])
+    if (url.pathname === "/project" || url.pathname === "/project/current") {
+      const project = {
+        id: current.projectID,
+        worktree: current.directory,
+        vcs: "git",
+        time: { created: 1, updated: 1 },
+        sandboxes: [],
+      }
+      return json(route, url.pathname === "/project" ? [project] : project)
+    }
+    if (url.pathname === "/path")
+      return json(route, {
+        state: current.directory,
+        config: current.directory,
+        worktree: current.directory,
+        directory: current.directory,
+        home: current.directory,
+      })
+    if (url.pathname === "/vcs") return json(route, { branch: "main", default_branch: "main" })
+    return json(route, {})
+  })
+}
+
+function json(route: Route, body: unknown, status = 200) {
+  return route.fulfill({
+    status,
+    contentType: "application/json",
+    headers: { "access-control-allow-origin": "*" },
+    body: JSON.stringify(body),
+  })
+}
+
+function sse(route: Route) {
+  return route.fulfill({ status: 200, contentType: "text/event-stream", body: ": ok\n\n" })
+}

packages/app/e2e/regression/prompt-thinking-level.spec.ts

@@ -66,7 +66,7 @@ test("shows the V2 thinking level control while relevant", async ({ page }) => {
   await expect(control).toBeVisible()
 
   await control.locator('[data-action="prompt-model-variant"]').click()
-  const high = page.getByRole("option", { name: "high" })
+  const high = page.getByRole("menuitemradio", { name: "high" })
   await expect(high).toBeVisible()
   await page.mouse.move(0, 0)
   await expect(control).toBeVisible()

packages/app/e2e/regression/remote-tab-busy.spec.ts

@@ -0,0 +1,109 @@
+import { expect, test, type Page, type Route } from "@playwright/test"
+import { base64Encode } from "@opencode-ai/core/util/encode"
+
+const serverA = "http://127.0.0.1:4096"
+const serverB = "http://127.0.0.1:4097"
+const sessionA = session("ses_server_a", "C:/server-a", "Server A session")
+const sessionB = session("ses_server_b", "/home/server-b", "Server B session")
+
+test("tab busy indicator reflects the tab server's own session status", async ({ page }) => {
+  await mockServers(page)
+  await page.addInitScript(
+    ({ serverA, serverB, sessionA, sessionB }) => {
+      localStorage.setItem("settings.v3", JSON.stringify({ general: { newLayoutDesigns: true } }))
+      localStorage.setItem("opencode.global.dat:server", JSON.stringify({ list: [serverB] }))
+      localStorage.setItem(
+        "opencode.window.browser.dat:tabs",
+        JSON.stringify([
+          { type: "session", server: serverA, sessionId: sessionA },
+          { type: "session", server: serverB, sessionId: sessionB },
+        ]),
+      )
+    },
+    { serverA, serverB, sessionA: sessionA.id, sessionB: sessionB.id },
+  )
+
+  const hrefA = `/server/${base64Encode(serverA)}/session/${sessionA.id}`
+  const hrefB = `/server/${base64Encode(serverB)}/session/${sessionB.id}`
+  await page.goto(hrefA)
+  await expect(page.getByText(sessionA.title).first()).toBeVisible()
+
+  // Session B is busy on server B while server A stays the active server, so the
+  // busy indicator must come from the tab server's status, not the active server's.
+  const tabB = page.locator(`[data-titlebar-tab-slot]:has(a[href="${hrefB}"])`)
+  await expect(tabB.locator('[data-component="session-progress-indicator-v2"]')).toBeVisible()
+
+  const tabA = page.locator(`[data-titlebar-tab-slot]:has(a[href="${hrefA}"])`)
+  await expect(tabA.locator("[data-titlebar-tab-title]")).toHaveText(sessionA.title)
+  await expect(tabA.locator('[data-component="session-progress-indicator-v2"]')).toHaveCount(0)
+})
+
+function session(id: string, directory: string, title: string) {
+  return {
+    id,
+    slug: id,
+    projectID: `project-${id}`,
+    directory,
+    title,
+    version: "dev",
+    time: { created: 1, updated: 1 },
+  }
+}
+
+async function mockServers(page: Page) {
+  await page.route("**/*", async (route) => {
+    const url = new URL(route.request().url())
+    if (url.origin !== serverA && url.origin !== serverB) return route.fallback()
+    const current = url.origin === serverA ? sessionA : sessionB
+    const directory = url.searchParams.get("directory")
+    if (directory && directory !== current.directory) return json(route, { name: "InvalidDirectory" }, 500)
+    if (url.pathname === "/global/event" || url.pathname === "/event") return sse(route)
+    if (url.pathname === "/global/health") return json(route, { healthy: true })
+    if (url.pathname === "/session/status")
+      return json(route, url.origin === serverB ? { [sessionB.id]: { type: "busy" } } : {})
+    if (url.pathname === "/session") return json(route, [current])
+    if (url.pathname === `/session/${current.id}`) return json(route, current)
+    if (/^\/session\/[^/]+$/.test(url.pathname)) return json(route, { name: "NotFoundError" }, 404)
+    if (url.pathname === `/session/${current.id}/message`) return json(route, [])
+    if (/^\/session\/[^/]+\/(children|todo|diff)$/.test(url.pathname)) return json(route, [])
+    if (["/skill", "/command", "/lsp", "/formatter", "/permission", "/question", "/vcs/diff"].includes(url.pathname))
+      return json(route, [])
+    if (["/global/config", "/config", "/provider/auth", "/mcp"].includes(url.pathname)) return json(route, {})
+    if (url.pathname === "/provider")
+      return json(route, { all: [], connected: [], default: { providerID: "", modelID: "" } })
+    if (url.pathname === "/agent") return json(route, [{ name: "build", mode: "primary" }])
+    if (url.pathname === "/project" || url.pathname === "/project/current") {
+      const project = {
+        id: current.projectID,
+        worktree: current.directory,
+        vcs: "git",
+        time: { created: 1, updated: 1 },
+        sandboxes: [],
+      }
+      return json(route, url.pathname === "/project" ? [project] : project)
+    }
+    if (url.pathname === "/path")
+      return json(route, {
+        state: current.directory,
+        config: current.directory,
+        worktree: current.directory,
+        directory: current.directory,
+        home: current.directory,
+      })
+    if (url.pathname === "/vcs") return json(route, { branch: "main", default_branch: "main" })
+    return json(route, {})
+  })
+}
+
+function json(route: Route, body: unknown, status = 200) {
+  return route.fulfill({
+    status,
+    contentType: "application/json",
+    headers: { "access-control-allow-origin": "*" },
+    body: JSON.stringify(body),
+  })
+}
+
+function sse(route: Route) {
+  return route.fulfill({ status: 200, contentType: "text/event-stream", body: ": ok\n\n" })
+}

packages/app/e2e/regression/review-image-flash.spec.ts

@@ -0,0 +1,202 @@
+import { expect, test, type Page } from "@playwright/test"
+import { base64Encode } from "@opencode-ai/core/util/encode"
+import { mockOpenCodeServer } from "../utils/mock-server"
+import { expectAppVisible, expectSessionTitle } from "../utils/waits"
+
+const directory = "C:/OpenCode/ReviewImageFlashRegression"
+const sessionID = "ses_review_image_flash_regression"
+const title = "Review image flash regression"
+const imageFile = "assets/preview.png"
+
+test("clicking an image file in the v2 review pane does not blank the panel", async ({ page }) => {
+  await openReview(page)
+  await installReviewFlashProbe(page)
+
+  await page.getByRole("button", { name: /preview\.png/ }).click()
+  await waitForReviewFlashProbe(page, 400)
+  const trace = await collectReviewFlashProbe(page)
+  const bad = trace.samples.filter((sample) => sample.blank || sample.blackCenter)
+
+  expect(trace.samples.length).toBeGreaterThan(0)
+  expect(
+    bad,
+    JSON.stringify({ bad: bad.slice(0, 8), first: trace.samples.slice(0, 8), last: trace.samples.slice(-4) }, null, 2),
+  ).toEqual([])
+})
+
+async function openReview(page: Page) {
+  await page.setViewportSize({ width: 960, height: 900 })
+  await page.addInitScript(() => {
+    localStorage.setItem("settings.v3", JSON.stringify({ general: { newLayoutDesigns: true } }))
+  })
+  await mockOpenCodeServer(page, {
+    directory,
+    project: {
+      id: "proj_review_image_flash_regression",
+      worktree: directory,
+      vcs: "git",
+      name: "review-image-flash-regression",
+      time: { created: 1700000000000, updated: 1700000000000 },
+      sandboxes: [],
+    },
+    provider: { all: [], connected: [], default: {} },
+    sessions: [
+      {
+        id: sessionID,
+        slug: "review-image-flash-regression",
+        projectID: "proj_review_image_flash_regression",
+        directory,
+        title,
+        version: "dev",
+        time: { created: 1700000000000, updated: 1700000000000 },
+      },
+    ],
+    vcsDiff: [
+      {
+        file: "src/example.ts",
+        additions: 1,
+        deletions: 1,
+        status: "modified",
+        patch:
+          "diff --git a/src/example.ts b/src/example.ts\n--- a/src/example.ts\n+++ b/src/example.ts\n@@ -1 +1 @@\n-export const value = 'before'\n+export const value = 'after'\n",
+      },
+      {
+        file: imageFile,
+        patch: "",
+        additions: 1,
+        deletions: 0,
+        status: "added",
+      },
+    ],
+    fileContent: async (path) => {
+      if (path !== imageFile) return undefined
+      await new Promise((resolve) => setTimeout(resolve, 250))
+      return {
+        type: "binary",
+        content: "iVBORw0KGgo=",
+        encoding: "base64",
+        mimeType: "image/png",
+      }
+    },
+    fileList: (path) => {
+      if (!path) {
+        return [
+          { name: "assets", path: "assets", absolute: `${directory}/assets`, type: "directory", ignored: false },
+          { name: "src", path: "src", absolute: `${directory}/src`, type: "directory", ignored: false },
+        ]
+      }
+      if (path === "assets") {
+        return [
+          {
+            name: "preview.png",
+            path: imageFile,
+            absolute: `${directory}/${imageFile}`,
+            type: "file",
+            ignored: false,
+          },
+        ]
+      }
+      if (path === "src") {
+        return [
+          {
+            name: "example.ts",
+            path: "src/example.ts",
+            absolute: `${directory}/src/example.ts`,
+            type: "file",
+            ignored: false,
+          },
+        ]
+      }
+      return []
+    },
+    pageMessages: () => ({
+      items: [
+        {
+          info: {
+            id: "msg_review_image_flash_regression",
+            sessionID,
+            role: "user",
+            time: { created: 1700000000000 },
+            summary: { diffs: [] },
+            agent: "build",
+            model: { providerID: "opencode", modelID: "test" },
+          },
+          parts: [
+            {
+              id: "prt_review_image_flash_regression",
+              sessionID,
+              messageID: "msg_review_image_flash_regression",
+              type: "text",
+              text: "Review this change.",
+            },
+          ],
+        },
+      ],
+    }),
+  })
+
+  await page.goto(`/${base64Encode(directory)}/session/${sessionID}`)
+  await expectSessionTitle(page, title)
+  await page.getByRole("button", { name: "Toggle review" }).click()
+  await expectAppVisible(page.locator('#review-panel [data-component="session-review-v2"]'))
+  await expectAppVisible(page.getByRole("button", { name: /preview\.png/ }))
+}
+
+async function installReviewFlashProbe(page: Page) {
+  await page.evaluate(() => {
+    const samples: Array<{
+      observedAtMs: number
+      blank: boolean
+      blackCenter: boolean
+      text: string
+      background: string
+    }> = []
+    const startedAt = performance.now()
+    const sample = () => {
+      const panel = document.querySelector<HTMLElement>('#review-panel [data-component="session-review-v2"]')
+      const rect = panel?.getBoundingClientRect()
+      const center = rect
+        ? document.elementFromPoint(rect.left + rect.width / 2, rect.top + rect.height / 2)
+        : undefined
+      const background = center instanceof Element ? getComputedStyle(center).backgroundColor : ""
+      samples.push({
+        observedAtMs: performance.now() - startedAt,
+        blank: !panel || panel.textContent?.trim().length === 0,
+        blackCenter: background === "rgb(0, 0, 0)",
+        text: panel?.textContent?.trim().slice(0, 80) ?? "",
+        background,
+      })
+      if (performance.now() - startedAt < 500) requestAnimationFrame(sample)
+    }
+    document.addEventListener(
+      "click",
+      (event) => {
+        const target = event.target instanceof Element ? event.target : undefined
+        if (!target?.closest('[data-slot="file-tree-v2-row"]')) return
+        requestAnimationFrame(sample)
+      },
+      { capture: true, once: true },
+    )
+    ;(window as Window & { __reviewImageFlash?: { samples: typeof samples; startedAt: number } }).__reviewImageFlash = {
+      samples,
+      startedAt,
+    }
+  })
+}
+
+async function waitForReviewFlashProbe(page: Page, durationMs: number) {
+  await page.waitForFunction((durationMs) => {
+    const state = (window as Window & { __reviewImageFlash?: { samples: unknown[]; startedAt: number } })
+      .__reviewImageFlash
+    return !!state && state.samples.length > 0 && performance.now() - state.startedAt >= durationMs
+  }, durationMs)
+}
+
+async function collectReviewFlashProbe(page: Page) {
+  return page.evaluate(() => {
+    return (window as Window & { __reviewImageFlash?: { samples: unknown[]; startedAt: number } }).__reviewImageFlash!
+  }) as Promise<{
+    startedAt: number
+    samples: Array<{ observedAtMs: number; blank: boolean; blackCenter: boolean; text: string; background: string }>
+  }>
+}

packages/app/e2e/regression/review-line-comment.spec.ts

@@ -0,0 +1,157 @@
+import { expect, test, type Page } from "@playwright/test"
+import { base64Encode } from "@opencode-ai/core/util/encode"
+import { mockOpenCodeServer } from "../utils/mock-server"
+import { expectAppVisible, expectSessionTitle } from "../utils/waits"
+
+const directory = "C:/OpenCode/ReviewLineCommentRegression"
+const sessionID = "ses_review_line_comment_regression"
+const title = "Review line comment regression"
+
+test.beforeEach(async ({ page }) => {
+  await openReview(page)
+})
+
+test("opens the comment editor when code is clicked", async ({ page }) => {
+  const review = page.locator('[data-component="session-review"]')
+  const line = review.getByText("export const value = 'after'", { exact: true })
+  await expectAppVisible(line)
+  await line.click()
+
+  await expect(review.getByRole("textbox")).toBeVisible()
+})
+
+test("opens the comment editor when a line number is clicked", async ({ page }) => {
+  const review = page.locator('[data-component="session-review"]')
+  const lineNumber = review.locator('[data-column-number="1"]').last()
+  await expectAppVisible(lineNumber)
+  await lineNumber.click()
+
+  await expect(review.getByRole("textbox")).toBeVisible()
+})
+
+test("opens the comment editor for a line number range", async ({ page }) => {
+  const review = page.locator('[data-component="session-review"]')
+  const start = review.locator('[data-column-number="1"]').last()
+  const end = review.locator('[data-column-number="3"]').last()
+  await expectAppVisible(start)
+  await expectAppVisible(end)
+
+  const from = await start.boundingBox()
+  const to = await end.boundingBox()
+  if (!from || !to) throw new Error("Missing line number bounds")
+  await page.mouse.move(from.x + from.width / 2, from.y + from.height / 2)
+  await page.mouse.down()
+  await page.mouse.move(to.x + to.width / 2, to.y + to.height / 2)
+  await page.mouse.up()
+
+  await expect(review.getByRole("textbox")).toBeVisible()
+})
+
+test("shows a comment button when a line number is hovered", async ({ page }) => {
+  const review = page.locator('[data-component="session-review"]')
+  const lineNumber = review.locator('[data-column-number="1"]').last()
+  await expectAppVisible(lineNumber)
+
+  const comment = review.getByRole("button", { name: "Comment", exact: true })
+  await expect(async () => {
+    await page.mouse.move(0, 0)
+    await lineNumber.hover()
+    await expect(comment).toBeVisible({ timeout: 500 })
+    await comment.click({ timeout: 500 })
+  }).toPass()
+  await expect(review.getByRole("textbox")).toBeVisible()
+})
+
+test("stages a submitted line comment in the prompt context", async ({ page }) => {
+  const requests: string[] = []
+  page.on("request", (request) => {
+    if (request.method() !== "GET") requests.push(`${request.method()} ${new URL(request.url()).pathname}`)
+  })
+
+  const review = page.locator('[data-component="session-review"]')
+  await review.getByText("export const value = 'after'", { exact: true }).click()
+  await review.getByRole("textbox").fill("Use the existing value instead")
+  await review.locator('[data-slot="line-comment-action"][data-variant="primary"]').click()
+
+  await expect(review.getByText("Use the existing value instead", { exact: true })).toBeVisible()
+  await page.getByRole("tab", { name: "Session" }).click()
+  const context = page.getByText("Use the existing value instead", { exact: true }).last()
+  await expect(context).toBeVisible()
+  await expect(context.locator("..")).toContainText("review.ts:2")
+  expect(requests).toEqual([])
+})
+
+async function openReview(page: Page) {
+  await page.setViewportSize({ width: 700, height: 900 })
+  await mockOpenCodeServer(page, {
+    directory,
+    project: {
+      id: "proj_review_line_comment_regression",
+      worktree: directory,
+      vcs: "git",
+      name: "review-line-comment-regression",
+      time: { created: 1700000000000, updated: 1700000000000 },
+      sandboxes: [],
+    },
+    provider: { all: [], connected: [], default: {} },
+    sessions: [
+      {
+        id: sessionID,
+        slug: "review-line-comment-regression",
+        projectID: "proj_review_line_comment_regression",
+        directory,
+        title,
+        version: "dev",
+        time: { created: 1700000000000, updated: 1700000000000 },
+      },
+    ],
+    vcsDiff: [
+      {
+        file: "src/review.ts",
+        additions: 1,
+        deletions: 1,
+        status: "modified",
+        patch:
+          "diff --git a/src/review.ts b/src/review.ts\n--- a/src/review.ts\n+++ b/src/review.ts\n@@ -1,3 +1,3 @@\n export const first = 1\n-export const value = 'before'\n+export const value = 'after'\n export const last = 3\n",
+      },
+    ],
+    pageMessages: () => ({
+      items: [
+        {
+          info: {
+            id: "msg_review_line_comment_regression",
+            sessionID,
+            role: "user",
+            time: { created: 1700000000000 },
+            summary: { diffs: [] },
+            agent: "build",
+            model: { providerID: "opencode", modelID: "test" },
+          },
+          parts: [
+            {
+              id: "prt_review_line_comment_regression",
+              sessionID,
+              messageID: "msg_review_line_comment_regression",
+              type: "text",
+              text: "Review this change.",
+            },
+          ],
+        },
+      ],
+    }),
+  })
+
+  await page.goto(`/${base64Encode(directory)}/session/${sessionID}`)
+  await expectSessionTitle(page, title)
+  const diffResponse = page.waitForResponse((response) => new URL(response.url()).pathname === "/vcs/diff")
+  await page.getByRole("tab", { name: "Changes" }).click()
+  expect(await (await diffResponse).json()).toHaveLength(1)
+
+  const review = page.locator('[data-component="session-review"]')
+  await expectAppVisible(review)
+  await review
+    .getByRole("heading", { name: /review\.ts/ })
+    .getByRole("button")
+    .first()
+    .click()
+}

packages/app/e2e/regression/review-tab-switch.spec.ts

@@ -0,0 +1,129 @@
+import { base64Encode } from "@opencode-ai/core/util/encode"
+import { expect, test, type Page } from "@playwright/test"
+import { mockOpenCodeServer } from "../utils/mock-server"
+import { expectAppVisible, expectSessionTitle } from "../utils/waits"
+
+const directory = "C:/OpenCode/ReviewTabSwitch"
+const projectID = "proj_review_tab_switch"
+const sessionA = "ses_review_tab_a"
+const sessionB = "ses_review_tab_b"
+const titleA = "Alpha session"
+const titleB = "Beta session"
+const server = `http://${process.env.PLAYWRIGHT_SERVER_HOST ?? "127.0.0.1"}:${process.env.PLAYWRIGHT_SERVER_PORT ?? "4096"}`
+// Marks the review pane DOM node so a remount (fresh node) is detectable.
+const PROBE = "original"
+
+test.use({ viewport: { width: 1440, height: 900 } })
+
+// The v2 review pane's diff data is workspace-scoped: switching between session
+// tabs in the same workspace must update its parameters reactively instead of
+// tearing the pane down and remounting it (which flickers).
+test("keeps the v2 review pane mounted when switching session tabs in a workspace", async ({ page }) => {
+  await setup(page)
+
+  await page.goto(sessionHref(sessionA))
+  await expectSessionTitle(page, titleA)
+
+  await page.getByRole("button", { name: "Toggle review" }).click()
+  const review = page.locator('#review-panel [data-component="session-review-v2"]')
+  await expectAppVisible(review)
+  await expectAppVisible(page.getByRole("button", { name: /example\.ts/ }))
+  await writeProbe(page)
+
+  await switchTab(page, titleB)
+  await expectSessionTitle(page, titleB)
+  await expectAppVisible(review)
+  expect(await readProbe(page)).toBe(PROBE)
+
+  await switchTab(page, titleA)
+  await expectSessionTitle(page, titleA)
+  await expectAppVisible(review)
+  expect(await readProbe(page)).toBe(PROBE)
+})
+
+type Probed = HTMLElement & { __e2eProbe?: string }
+
+async function switchTab(page: Page, title: string) {
+  await page.locator("[data-titlebar-tab-slot]", { hasText: title }).click()
+}
+
+async function writeProbe(page: Page) {
+  await page.locator('#review-panel [data-component="session-review-v2"]').evaluate((el, probe) => {
+    ;(el as Probed).__e2eProbe = probe
+  }, PROBE)
+}
+
+async function readProbe(page: Page) {
+  return page.locator('#review-panel [data-component="session-review-v2"]').evaluate((el) => (el as Probed).__e2eProbe)
+}
+
+async function setup(page: Page) {
+  await mockOpenCodeServer(page, {
+    directory,
+    project: {
+      id: projectID,
+      worktree: directory,
+      vcs: "git",
+      name: "review-tab-switch",
+      time: { created: 1700000000000, updated: 1700000000000 },
+      sandboxes: [],
+    },
+    provider: {
+      all: [
+        {
+          id: "opencode",
+          name: "OpenCode",
+          models: { test: { id: "test", name: "Test", limit: { context: 200_000 } } },
+        },
+      ],
+      connected: ["opencode"],
+      default: { providerID: "opencode", modelID: "test" },
+    },
+    sessions: [session(sessionA, titleA, 1700000000000), session(sessionB, titleB, 1700000001000)],
+    vcsDiff: [
+      {
+        file: "src/example.ts",
+        additions: 1,
+        deletions: 1,
+        status: "modified",
+        patch:
+          "diff --git a/src/example.ts b/src/example.ts\n--- a/src/example.ts\n+++ b/src/example.ts\n@@ -1 +1 @@\n-export const value = 'before'\n+export const value = 'after'\n",
+      },
+    ],
+    pageMessages: () => ({ items: [] }),
+  })
+
+  await page.addInitScript(
+    ({ directory, server, sessions }) => {
+      localStorage.setItem("settings.v3", JSON.stringify({ general: { newLayoutDesigns: true } }))
+      localStorage.setItem(
+        "opencode.global.dat:server",
+        JSON.stringify({
+          projects: { local: [{ worktree: directory, expanded: true }] },
+          lastProject: { local: directory },
+        }),
+      )
+      localStorage.setItem(
+        "opencode.window.browser.dat:tabs",
+        JSON.stringify(sessions.map((sessionId: string) => ({ type: "session", server, sessionId }))),
+      )
+    },
+    { directory, server, sessions: [sessionA, sessionB] },
+  )
+}
+
+function session(id: string, title: string, created: number) {
+  return {
+    id,
+    slug: id,
+    projectID,
+    directory,
+    title,
+    version: "dev",
+    time: { created, updated: created },
+  }
+}
+
+function sessionHref(sessionID: string) {
+  return `/server/${base64Encode(server)}/session/${sessionID}`
+}

packages/app/e2e/regression/session-request-docks.spec.ts

@@ -0,0 +1,155 @@
+import { base64Encode } from "@opencode-ai/core/util/encode"
+import { expect, test, type Page } from "@playwright/test"
+import { mockOpenCodeServer } from "../utils/mock-server"
+import { expectSessionTitle } from "../utils/waits"
+
+const directory = "C:/OpenCode/RequestDocks"
+const projectID = "proj_request_docks"
+const sessionID = "ses_request_docks"
+const title = "Request dock regression"
+
+test("shows a pending question dock", async ({ page }) => {
+  await mockServer(page, {
+    questions: [
+      {
+        id: "question-request",
+        sessionID,
+        questions: [
+          {
+            header: "Implementation",
+            question: "Which implementation should be used?",
+            options: [
+              { label: "Minimal", description: "Use the smallest correct change" },
+              { label: "Extended", description: "Include additional behavior" },
+            ],
+          },
+        ],
+      },
+    ],
+  })
+
+  await page.goto(`/${base64Encode(directory)}/session/${sessionID}`)
+  await expectSessionTitle(page, title)
+
+  const question = page.locator('[data-component="dock-prompt"][data-kind="question"]')
+  await expect(question).toBeVisible()
+  await expect(question.getByText("Which implementation should be used?")).toBeVisible()
+  await expect(question.getByRole("radio", { name: /Minimal/ })).toBeVisible()
+  await expect(question.getByRole("radio", { name: /Extended/ })).toBeVisible()
+  await expect(page.locator('[data-component="session-composer"]')).toHaveCount(0)
+
+  const rejectRequests: string[] = []
+  page.on("request", (request) => {
+    if (request.method() !== "POST") return
+    if (new URL(request.url()).pathname === "/question/question-request/reject") rejectRequests.push(request.url())
+  })
+
+  await question.locator('[data-component="icon-button"][data-icon="chevron-down"]').click()
+  await expect(question).toBeVisible()
+  await expect(question.getByText("Which implementation should be used?")).toBeVisible()
+  await expect(question.getByText("Select one answer")).toBeHidden()
+  await expect(question.getByRole("radio", { name: /Minimal/ })).toBeHidden()
+  await expect(question.getByRole("radio", { name: /Extended/ })).toBeHidden()
+  await expect(question.getByRole("button", { name: "Dismiss" })).toBeVisible()
+  await expect(question.getByRole("button", { name: "Submit" })).toBeVisible()
+  await expect(page.locator('[data-component="question-minimized-dock"]')).toHaveCount(0)
+  expect(rejectRequests).toEqual([])
+
+  await question.locator('[data-component="icon-button"][data-icon="chevron-down"]').click()
+  await expect(question).toBeVisible()
+  await expect(question.getByText("Which implementation should be used?")).toBeVisible()
+  await expect(question.getByRole("radio", { name: /Minimal/ })).toBeVisible()
+  expect(rejectRequests).toEqual([])
+
+  await question.getByRole("radio", { name: /Minimal/ }).click()
+  const reply = page.waitForRequest(
+    (request) => request.method() === "POST" && new URL(request.url()).pathname === "/question/question-request/reply",
+  )
+  await question.getByRole("button", { name: "Submit" }).click()
+  expect((await reply).postDataJSON()).toEqual({ answers: [["Minimal"]] })
+})
+
+test("shows a pending permission dock", async ({ page }) => {
+  await mockServer(page, {
+    permissions: [
+      {
+        id: "permission-request",
+        sessionID,
+        permission: "bash",
+        patterns: ["git status", "git diff"],
+        metadata: {},
+        always: [],
+      },
+    ],
+  })
+
+  await page.goto(`/${base64Encode(directory)}/session/${sessionID}`)
+  await expectSessionTitle(page, title)
+
+  const permission = page.locator('[data-component="dock-prompt"][data-kind="permission"]')
+  await expect(permission).toBeVisible()
+  await expect(permission.getByText("git status")).toBeVisible()
+  await expect(permission.getByText("git diff")).toBeVisible()
+  await expect(permission.locator('[data-slot="permission-footer-actions"] button')).toHaveCount(3)
+  await expect(page.locator('[data-component="session-composer"]')).toHaveCount(0)
+
+  const reply = page.waitForRequest((request) => request.method() === "POST")
+  await permission.getByRole("button", { name: "Allow once" }).click()
+  const request = await reply
+  expect(new URL(request.url()).pathname).toBe(`/session/${sessionID}/permissions/permission-request`)
+  expect(request.postDataJSON()).toEqual({ response: "once" })
+})
+
+async function mockServer(
+  page: Page,
+  requests: {
+    permissions?: unknown[] | (() => unknown[])
+    questions?: unknown[] | (() => unknown[])
+  },
+) {
+  await mockOpenCodeServer(page, {
+    directory,
+    project: {
+      id: projectID,
+      worktree: directory,
+      vcs: "git",
+      name: "request-docks",
+      time: { created: 1700000000000, updated: 1700000000000 },
+      sandboxes: [],
+    },
+    provider: {
+      all: [
+        {
+          id: "opencode",
+          name: "OpenCode",
+          models: {
+            "claude-opus-4-6": {
+              id: "claude-opus-4-6",
+              name: "Claude Opus 4.6",
+              limit: { context: 200_000 },
+            },
+          },
+        },
+      ],
+      connected: ["opencode"],
+      default: { providerID: "opencode", modelID: "claude-opus-4-6" },
+    },
+    sessions: [
+      {
+        id: sessionID,
+        slug: "request-docks",
+        projectID,
+        directory,
+        title,
+        version: "dev",
+        time: { created: 1700000000000, updated: 1700000000000 },
+      },
+    ],
+    pageMessages: () => ({ items: [] }),
+    permissions: requests.permissions,
+    questions: requests.questions,
+  })
+  await page.addInitScript(() => {
+    localStorage.setItem("settings.v3", JSON.stringify({ general: { newLayoutDesigns: true } }))
+  })
+}

packages/app/e2e/regression/session-timeline-accessibility.spec.ts

@@ -0,0 +1,22 @@
+import { expect, test } from "@playwright/test"
+import { assistantMessage, setupTimeline, shell, userMessage } from "../performance/timeline-stability/fixture"
+
+test("space activates a focused timeline button instead of scrolling", async ({ page }) => {
+  const shellID = "prt_space_button_shell"
+  await setupTimeline(page, {
+    messages: [userMessage(), assistantMessage([shell(shellID, "completed", lines(5))])],
+    settings: { shellToolPartsExpanded: false },
+    reducedMotion: true,
+  })
+  const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
+  const trigger = page.locator(`[data-timeline-part-id="${shellID}"] [data-slot="collapsible-trigger"]`)
+  await trigger.focus()
+  const before = await scroller.evaluate((element) => element.scrollTop)
+  await trigger.press("Space")
+  await expect(trigger).toHaveAttribute("aria-expanded", "true")
+  expect(await scroller.evaluate((element) => element.scrollTop)).toBe(before)
+})
+
+function lines(count: number) {
+  return Array.from({ length: count }, (_, index) => `line ${index + 1}`).join("\n")
+}

packages/app/e2e/regression/session-timeline-collapse-state.spec.ts

@@ -261,7 +261,6 @@ async function configurePage(page: Page) {
           editToolPartsExpanded: true,
           shellToolPartsExpanded: true,
           showReasoningSummaries: true,
-          showSessionProgressBar: true,
         },
       }),
     )

packages/app/e2e/regression/session-timeline-context-resize.spec.ts

@@ -1,6 +1,13 @@
 import { expect, test, type Page } from "@playwright/test"
 import { mockOpenCodeServer } from "../utils/mock-server"
 import { expectAppVisible, expectSessionTitle } from "../utils/waits"
+import {
+  analyzeVisualObservations,
+  defineVisualRegions,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../utils/visual-stability"
 
 const directory = "C:/OpenCode/ContextResizeRegression"
 const projectID = "proj_context_resize_regression"
@@ -36,6 +43,82 @@ test.describe("regression: session timeline context group resize", () => {
     expect(visibleOverlap).toEqual([])
     expect(samples.at(-1)?.expanded).toBe("true")
   })
+
+  test("paints a stable exploring to explored transition", async ({ page }) => {
+    const events: { directory: string; payload: Record<string, unknown> }[] = []
+    await page.setViewportSize({ width: 1400, height: 900 })
+    await mockServer(page, events, [
+      ...Array.from({ length: 8 }, (_, index) => turn(index, false)).flat(),
+      ...turn(10, true, "running"),
+    ])
+    await configurePage(page)
+
+    await page.goto(`/${base64Encode(directory)}/session/${sessionID}`)
+    await expectSessionTitle(page, title)
+    const devtools = await page.context().newCDPSession(page)
+    await devtools.send("Emulation.setCPUThrottlingRate", { rate: 4 })
+    const context = page.locator(`[data-timeline-part-ids="${contextIDs.join(",")}"]`).first()
+    await expectAppVisible(context)
+    await expect(context.locator('[data-component="tool-status-title"]')).toHaveAttribute("aria-label", "Exploring")
+
+    const contextSelector = `[data-timeline-part-ids="${contextIDs.join(",")}"]`
+    const regions = defineVisualRegions({
+      status: {
+        selector: `${contextSelector} [data-component="tool-status-title"]`,
+        opacitySelectors: ['[data-slot="tool-status-active"]', '[data-slot="tool-status-done"]'],
+      },
+      context: { selector: contextSelector, closest: '[data-timeline-row="AssistantPart"]' },
+      following: {
+        selector: `[data-timeline-part-id="${followingTextID}"]`,
+        closest: '[data-timeline-row="AssistantPart"]',
+      },
+    })
+    await startVisualProbe(page, regions)
+    for (const [index, delay] of [120, 350, 80, 500].entries()) {
+      events.push({
+        directory,
+        payload: {
+          type: "message.part.updated",
+          properties: {
+            part: contextTool(
+              contextIDs[index]!,
+              id("msg_assistant", 10),
+              ["read", "glob", "grep", "list"][index]!,
+              [
+                { filePath: "src/recent-a.ts" },
+                { path: directory, pattern: "**/*.ts" },
+                { path: directory, pattern: "Explored" },
+                { path: "src" },
+              ][index]!,
+            ),
+          },
+        },
+      })
+      await page.waitForTimeout(delay)
+    }
+
+    await expect(context.locator('[data-component="tool-status-title"]')).toHaveAttribute("aria-label", "Explored")
+    await page.waitForTimeout(700)
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    const labels = trace.samples
+      .map((sample) => sample.regions.status?.label)
+      .filter((value): value is string => !!value)
+      .filter((value, index, all) => value !== all[index - 1])
+    const issues = analyzeVisualObservations(
+      trace.samples,
+      visualPlan(regions, [
+        { type: "required", regions: ["context", "following"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all" },
+        { type: "label-stability", regions: "all" },
+        { type: "flow", regions: ["context", "following"] },
+      ]),
+    )
+
+    expect(labels).toEqual(["Exploring", "Explored"])
+    expect(issues, JSON.stringify(trace.samples, null, 2)).toEqual([])
+  })
 })
 
 async function configurePage(page: Page) {
@@ -47,7 +130,6 @@ async function configurePage(page: Page) {
           editToolPartsExpanded: true,
           shellToolPartsExpanded: true,
           showReasoningSummaries: true,
-          showSessionProgressBar: true,
         },
       }),
     )
@@ -129,7 +211,7 @@ async function sampleExpansion(page: Page) {
   )
 }
 
-function turn(index: number, target: boolean): Message[] {
+function turn(index: number, target: boolean, status: "running" | "completed" = "completed"): Message[] {
   const userID = id("msg_user", index)
   const assistantID = id("msg_assistant", index)
   return [
@@ -164,10 +246,22 @@ function turn(index: number, target: boolean): Message[] {
       },
       parts: target
         ? [
-            contextTool(contextIDs[0]!, assistantID, "read", { filePath: "src/recent-a.ts", offset: 0, limit: 120 }),
-            contextTool(contextIDs[1]!, assistantID, "glob", { path: directory, pattern: "**/*.ts" }),
-            contextTool(contextIDs[2]!, assistantID, "grep", { path: directory, pattern: "Explored", include: "*.ts" }),
-            contextTool(contextIDs[3]!, assistantID, "list", { path: "src" }),
+            contextTool(
+              contextIDs[0]!,
+              assistantID,
+              "read",
+              { filePath: "src/recent-a.ts", offset: 0, limit: 120 },
+              status,
+            ),
+            contextTool(contextIDs[1]!, assistantID, "glob", { path: directory, pattern: "**/*.ts" }, status),
+            contextTool(
+              contextIDs[2]!,
+              assistantID,
+              "grep",
+              { path: directory, pattern: "Explored", include: "*.ts" },
+              status,
+            ),
+            contextTool(contextIDs[3]!, assistantID, "list", { path: "src" }, status),
             {
               id: followingTextID,
               sessionID,
@@ -189,7 +283,13 @@ function turn(index: number, target: boolean): Message[] {
   ]
 }
 
-function contextTool(partID: string, messageID: string, tool: string, input: Record<string, unknown>) {
+function contextTool(
+  partID: string,
+  messageID: string,
+  tool: string,
+  input: Record<string, unknown>,
+  status: "running" | "completed" = "completed",
+) {
   return {
     id: partID,
     sessionID,
@@ -198,7 +298,7 @@ function contextTool(partID: string, messageID: string, tool: string, input: Rec
     callID: `call_${partID}`,
     tool,
     state: {
-      status: "completed",
+      status,
       input,
       output: `Completed ${tool}.\n${"detail line\n".repeat(8)}`,
       title: input.filePath || input.path || input.pattern || "completed",
@@ -208,13 +308,19 @@ function contextTool(partID: string, messageID: string, tool: string, input: Rec
   }
 }
 
-async function mockServer(page: Page) {
+async function mockServer(
+  page: Page,
+  events: { directory: string; payload: Record<string, unknown> }[] = [],
+  fixtureMessages = messages,
+) {
   await mockOpenCodeServer(page, {
     directory,
     project: project(),
     provider: provider(),
     sessions: [session()],
-    pageMessages: () => ({ items: messages }),
+    pageMessages: () => ({ items: fixtureMessages }),
+    events: () => events.splice(0, 1),
+    eventRetry: 50,
   })
 }
 

packages/app/e2e/regression/session-timeline-context-state.spec.ts

@@ -0,0 +1,31 @@
+import { expect, test } from "@playwright/test"
+import {
+  assistantMessage,
+  partUpdated,
+  setupTimeline,
+  toolPart,
+  userMessage,
+} from "../performance/timeline-stability/fixture"
+
+test("preserves a collapsed context group through count and status updates", async ({ page }) => {
+  const ids = ["prt_closed_01_read", "prt_closed_02_glob"]
+  const inputs = {
+    read: { filePath: "src/a.ts", offset: 0, limit: 120 },
+    glob: { path: ".", pattern: "**/*.ts" },
+  }
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage(
+        [toolPart(ids[0]!, "read", "running", inputs.read), toolPart(ids[1]!, "glob", "running", inputs.glob)],
+        { completed: false },
+      ),
+    ],
+  })
+  const group = page.locator(`[data-timeline-part-ids="${ids.join(",")}"]`)
+  const trigger = group.locator('[data-slot="collapsible-trigger"]')
+  await expect(trigger).toHaveAttribute("aria-expanded", "false")
+  await timeline.send(partUpdated(toolPart(ids[0]!, "read", "completed", inputs.read)), 100)
+  await timeline.send(partUpdated(toolPart(ids[1]!, "glob", "completed", inputs.glob)), 300)
+  await expect(trigger).toHaveAttribute("aria-expanded", "false")
+})

packages/app/e2e/regression/session-timeline-file-projection.spec.ts

@@ -0,0 +1,52 @@
+import { expect, test } from "@playwright/test"
+import { assistantMessage, setupTimeline, toolPart, userMessage } from "../performance/timeline-stability/fixture"
+
+test("renders completed write content", async ({ page }) => {
+  const id = "prt_file_projection_write"
+  await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([
+        toolPart(id, "write", "completed", { filePath: "src/write.ts", content: "export const written = true\n" }),
+      ]),
+    ],
+    settings: { editToolPartsExpanded: true },
+  })
+
+  await expect(page.locator(`[data-timeline-part-id="${id}"] [data-component="write-content"]`)).toBeVisible()
+})
+
+test("renders a completed single-file patch", async ({ page }) => {
+  const id = "prt_file_projection_single_patch"
+  await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([
+        toolPart(
+          id,
+          "apply_patch",
+          "completed",
+          { files: ["src/a.ts"] },
+          {
+            metadata: {
+              files: [
+                {
+                  filePath: "src/a.ts",
+                  relativePath: "src/a.ts",
+                  type: "update",
+                  additions: 1,
+                  deletions: 1,
+                  before: "export const value = 1\n",
+                  after: "export const value = 2\n",
+                },
+              ],
+            },
+          },
+        ),
+      ]),
+    ],
+    settings: { editToolPartsExpanded: true },
+  })
+
+  await expect(page.locator(`[data-timeline-part-id="${id}"] [data-component="apply-patch-file-diff"]`)).toBeVisible()
+})

packages/app/e2e/regression/session-timeline-file-state.spec.ts

@@ -0,0 +1,94 @@
+import { expect, test } from "@playwright/test"
+import {
+  assistantMessage,
+  partUpdated,
+  setupTimeline,
+  toolPart,
+  userMessage,
+} from "../performance/timeline-stability/fixture"
+
+test("updates edit diagnostics without resetting manual collapse state", async ({ page }) => {
+  const editID = "prt_diagnostics_edit"
+  const base = editPart(editID, [])
+  const timeline = await setupTimeline(page, {
+    messages: [userMessage(), assistantMessage([base])],
+    settings: { editToolPartsExpanded: true },
+  })
+  const trigger = page.locator(`[data-timeline-part-id="${editID}"] [data-slot="collapsible-trigger"]`).first()
+  await trigger.click()
+  await expect(trigger).toHaveAttribute("aria-expanded", "false")
+  await timeline.send(
+    partUpdated(editPart(editID, [diagnostic("First failure", 2), diagnostic("Second failure", 4)])),
+    300,
+  )
+  await expect(trigger).toHaveAttribute("aria-expanded", "false")
+  await timeline.send(partUpdated(editPart(editID, [])), 300)
+  await expect(trigger).toHaveAttribute("aria-expanded", "false")
+})
+
+test("preserves nested patch file state through outer collapse and reopen", async ({ page }) => {
+  const patchID = "prt_nested_patch"
+  const files = [patchFile("src/a.ts", "update"), patchFile("src/b.ts", "add"), patchFile("src/old.ts", "delete")]
+  await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([
+        toolPart(
+          patchID,
+          "apply_patch",
+          "completed",
+          { files: files.map((file) => file.filePath) },
+          { metadata: { files } },
+        ),
+      ]),
+    ],
+    settings: { editToolPartsExpanded: true },
+  })
+  const wrapper = page.locator(`[data-timeline-part-id="${patchID}"]`)
+  const outer = wrapper.locator('[data-slot="collapsible-trigger"]').first()
+  const deleted = wrapper.locator('[data-scope="apply-patch"] [data-type="delete"]')
+  await deleted.getByRole("button").click()
+  await expect(deleted.getByRole("button")).toHaveAttribute("aria-expanded", "true")
+  await outer.click()
+  await expect(outer).toHaveAttribute("aria-expanded", "false")
+  await outer.click()
+  await expect(outer).toHaveAttribute("aria-expanded", "true")
+  await expect(deleted.getByRole("button")).toHaveAttribute("aria-expanded", "true")
+})
+
+function patchFile(filePath: string, type: "add" | "update" | "delete") {
+  return {
+    filePath,
+    relativePath: filePath,
+    type,
+    additions: type === "delete" ? 0 : 4,
+    deletions: type === "add" ? 0 : 3,
+    before: type === "add" ? undefined : source(false),
+    after: type === "delete" ? undefined : source(true),
+  }
+}
+
+function editPart(id: string, diagnostics: Record<string, unknown>[]) {
+  return toolPart(
+    id,
+    "edit",
+    "completed",
+    { filePath: "src/edit.ts" },
+    {
+      metadata: {
+        filediff: { file: "src/edit.ts", additions: 1, deletions: 1, before: source(false), after: source(true) },
+        diagnostics,
+      },
+    },
+  )
+}
+
+function diagnostic(message: string, line: number) {
+  return { message, severity: 1, range: { start: { line, character: 0 }, end: { line, character: 2 } } }
+}
+
+function source(changed: boolean) {
+  return Array.from({ length: 12 }, (_, index) => `export const value${index} = ${changed ? index + 1 : index}\n`).join(
+    "",
+  )
+}

packages/app/e2e/regression/session-timeline-lifecycle-state.spec.ts

@@ -0,0 +1,94 @@
+import { expect, test } from "@playwright/test"
+import {
+  assistantMessage,
+  completedAssistantInfo,
+  messageUpdated,
+  partUpdated,
+  reasoningPart,
+  setupTimeline,
+  shell,
+  status,
+  textPart,
+  userMessage,
+} from "../performance/timeline-stability/fixture"
+
+for (const expanded of [false, true]) {
+  test(`preserves shell user intent from a ${expanded ? "expanded" : "collapsed"} default`, async ({ page }) => {
+    const id = `prt_shell_default_${expanded}`
+    const timeline = await setupTimeline(page, {
+      messages: [userMessage(), assistantMessage([shell(id, "completed", lines(3))])],
+      settings: { shellToolPartsExpanded: expanded },
+    })
+    const trigger = page.locator(`[data-timeline-part-id="${id}"] [data-slot="collapsible-trigger"]`)
+    await expect(trigger).toHaveAttribute("aria-expanded", String(expanded))
+    await trigger.click()
+    await expect(trigger).toHaveAttribute("aria-expanded", String(!expanded))
+
+    await timeline.send(partUpdated(shell(id, "completed", lines(6))), 180)
+    await timeline.send(partUpdated(textPart(`prt_sibling_${expanded}`, "Sibling content")), 180)
+    await timeline.send(status("busy"), 100)
+    await timeline.send(status("idle"), 250)
+    await expect(trigger).toHaveAttribute("aria-expanded", String(!expanded))
+  })
+}
+
+test("transitions thinking and hidden reasoning through busy to idle", async ({ page }) => {
+  const reasoningID = "prt_reasoning_hidden"
+  const assistant = assistantMessage([reasoningPart(reasoningID, "## Inspecting stability")], { completed: false })
+  const timeline = await setupTimeline(page, {
+    messages: [userMessage(), assistant],
+    settings: { showReasoningSummaries: false },
+    cpuRate: 4,
+  })
+  await timeline.send(status("busy"), 150)
+
+  await expect(page.locator('[data-timeline-row="Thinking"]')).toBeVisible()
+  await expect(page.getByText("Inspecting stability", { exact: true })).toBeVisible()
+  await expect(page.locator(`[data-timeline-part-id="${reasoningID}"]`)).toHaveCount(0)
+  await timeline.send(partUpdated(shell("prt_reasoning_shell", "running")), 160)
+  await expect(page.locator('[data-timeline-row="Thinking"]')).toBeVisible()
+  await timeline.send(partUpdated(shell("prt_reasoning_shell", "completed", "done")), 180)
+  await timeline.send(messageUpdated(completedAssistantInfo(assistant.info)), 100)
+  await timeline.send(status("idle"), 300)
+  await expect(page.locator('[data-timeline-row="Thinking"]')).toHaveCount(0)
+  await expect(page.locator(`[data-timeline-part-id="${reasoningID}"]`)).toHaveCount(0)
+})
+
+test("moves busy through retry and recovery to final idle content", async ({ page }) => {
+  const assistant = assistantMessage([], { completed: false })
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(undefined, {
+        summary: {
+          diffs: [
+            {
+              file: "src/retry.ts",
+              additions: 1,
+              deletions: 1,
+              patch: "@@ -1 +1 @@\n-export const retry = false\n+export const retry = true",
+            },
+          ],
+        },
+      }),
+      assistant,
+    ],
+  })
+  await timeline.send(status("busy"), 140)
+  await expect(page.locator('[data-timeline-row="Thinking"]')).toBeVisible()
+  await expect(page.locator('[data-timeline-row="DiffSummary"]')).toHaveCount(0)
+  await timeline.send(status("retry"), 180)
+  await expect(page.locator('[data-timeline-row="Retry"]')).toBeVisible()
+  await expect(page.locator('[data-timeline-row="Thinking"]')).toHaveCount(0)
+  await timeline.send(status("busy", 2), 180)
+  await expect(page.locator('[data-timeline-row="Thinking"]')).toBeVisible()
+  await timeline.send(partUpdated(textPart("prt_recovered", "Recovered response")), 140)
+  await timeline.send(messageUpdated(completedAssistantInfo(assistant.info)), 100)
+  await timeline.send(status("idle"), 350)
+  await expect(page.locator('[data-timeline-row="Retry"]')).toHaveCount(0)
+  await expect(page.locator('[data-timeline-row="Thinking"]')).toHaveCount(0)
+  await expect(page.locator('[data-timeline-row="DiffSummary"]')).toBeVisible()
+})
+
+function lines(count: number) {
+  return Array.from({ length: count }, (_, index) => `line ${index + 1}`).join("\n")
+}

packages/app/e2e/regression/session-timeline-locale-projection.spec.ts

@@ -0,0 +1,25 @@
+import { expect, test } from "@playwright/test"
+import { assistantMessage, setupTimeline, toolPart, userMessage } from "../performance/timeline-stability/fixture"
+
+for (const profile of [
+  { locale: "de", label: "Erkundet" },
+  { locale: "ar", label: "تم الاستكشاف" },
+] as const) {
+  test(`projects translated context status in ${profile.locale}`, async ({ page }) => {
+    const ids = [`prt_locale_${profile.locale}_01_read`, `prt_locale_${profile.locale}_02_glob`]
+    await setupTimeline(page, {
+      messages: [
+        userMessage(),
+        assistantMessage([
+          toolPart(ids[0]!, "read", "completed", { filePath: "src/a.ts" }),
+          toolPart(ids[1]!, "glob", "completed", { path: ".", pattern: "**/*.ts" }),
+        ]),
+      ],
+      locale: profile.locale,
+    })
+
+    const group = page.locator(`[data-timeline-part-ids="${ids.join(",")}"]`)
+    await expect(group.locator('[data-component="tool-status-title"]')).toHaveAttribute("aria-label", profile.label)
+    await expect(page.locator("html")).toHaveAttribute("lang", profile.locale)
+  })
+}

packages/app/e2e/regression/session-timeline-projection.spec.ts

@@ -0,0 +1,284 @@
+import { expect, test } from "@playwright/test"
+import {
+  assistantMessage,
+  setupTimeline,
+  status,
+  toolPart,
+  userMessage,
+  userText,
+  type PartSeed,
+} from "../performance/timeline-stability/fixture"
+
+test.describe("session timeline projection", () => {
+  test("renders every admitted tool family and hides timeline-only exclusions", async ({ page }) => {
+    const parts = [
+      toolPart("prt_01_read", "read", "completed", { filePath: "src/a.ts" }),
+      toolPart("prt_02_glob", "glob", "completed", { path: ".", pattern: "**/*.ts" }),
+      toolPart("prt_03_grep", "grep", "completed", { path: ".", pattern: "value" }),
+      toolPart("prt_04_list", "list", "completed", { path: "src" }),
+      toolPart("prt_webfetch", "webfetch", "completed", { url: "https://example.com" }),
+      toolPart(
+        "prt_websearch",
+        "websearch",
+        "completed",
+        { query: "timeline stability" },
+        { output: "https://example.com/result" },
+      ),
+      toolPart("prt_task", "task", "completed", { description: "Inspect timeline", subagent_type: "explore" }),
+      toolPart(
+        "prt_bash",
+        "bash",
+        "completed",
+        { command: "printf stable" },
+        { output: "stable", title: "printf stable" },
+      ),
+      editPart("prt_edit"),
+      toolPart("prt_write", "write", "completed", { filePath: "src/new.ts", content: "export const stable = true\n" }),
+      patchPart("prt_patch"),
+      toolPart("prt_todo", "todowrite", "completed", { todos: [{ content: "Hidden", status: "pending" }] }),
+      toolPart(
+        "prt_question",
+        "question",
+        "completed",
+        { questions: [{ question: "Keep stable?", header: "Stability", options: [] }] },
+        { metadata: { answers: [["Yes"]] } },
+      ),
+      toolPart("prt_skill", "skill", "completed", { name: "stability" }),
+      toolPart("prt_custom", "custom_mcp_tool", "completed", { target: "timeline", count: 2 }),
+    ]
+    await setupTimeline(page, { messages: [userMessage(), assistantMessage(parts)] })
+
+    await expect(
+      page.locator('[data-timeline-part-ids="prt_01_read,prt_02_glob,prt_03_grep,prt_04_list"]'),
+    ).toBeVisible()
+    for (const id of [
+      "prt_webfetch",
+      "prt_websearch",
+      "prt_task",
+      "prt_bash",
+      "prt_edit",
+      "prt_write",
+      "prt_patch",
+      "prt_question",
+      "prt_skill",
+      "prt_custom",
+    ]) {
+      await expect(page.locator(`[data-timeline-part-id="${id}"]`).first(), id).toBeVisible()
+    }
+    await expect(page.locator('[data-timeline-part-id="prt_todo"]')).toHaveCount(0)
+  })
+
+  test("projects gaps, dividers, assistant parts, and errors together", async ({ page }) => {
+    const firstUser = userMessage(
+      [
+        userText("The user made the following comment regarding lines 4 through 8 of src/a.ts: Keep this stable", {
+          id: "prt_comment",
+          synthetic: true,
+          metadata: {
+            opencodeComment: {
+              path: "src/a.ts",
+              selection: { startLine: 4, startChar: 0, endLine: 8, endChar: 0 },
+              comment: "Keep this stable",
+            },
+          },
+        }),
+        userText("Continue after the comment", { id: "prt_visible_user" }),
+      ],
+      { summary: { diffs: Array.from({ length: 11 }, (_, index) => summaryDiff(index)) } },
+    )
+    const aborted = assistantMessage(
+      [
+        { id: "prt_before_abort", type: "text", text: "Before interruption" },
+        { id: "prt_compaction", type: "compaction", auto: true },
+      ],
+      {
+        id: "msg_1001_assistant_aborted",
+        error: { name: "MessageAbortedError", data: { message: "Stopped" } },
+      },
+    )
+    const failed = assistantMessage([{ id: "prt_after_abort", type: "text", text: "After interruption" }], {
+      id: "msg_1002_assistant_failed",
+      error: {
+        name: "APIError",
+        data: {
+          message: JSON.stringify({ error: { type: "provider_error", message: "Visible provider failure" } }),
+          isRetryable: false,
+        },
+      },
+      created: 1700000003000,
+    })
+    const nextUser = userMessage([userText("Second turn", { id: "prt_second_user" })], {
+      id: "msg_2000_second_user",
+      created: 1700000005000,
+    })
+    const nextAssistant = assistantMessage([{ id: "prt_second_text", type: "text", text: "Second response" }], {
+      id: "msg_2001_second_assistant",
+      parentID: "msg_2000_second_user",
+      created: 1700000006000,
+    })
+    const timeline = await setupTimeline(page, { messages: [firstUser, aborted, failed, nextUser, nextAssistant] })
+    await timeline.send(status("idle"), 100)
+    const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
+    await scroller.evaluate((element) => (element.scrollTop = 0))
+
+    await expect(page.locator('[data-timeline-row="TurnDivider"]')).toHaveCount(1)
+    await expect(page.getByText("Session compacted", { exact: true })).toBeVisible()
+    await expect(page.getByText("Visible provider failure")).toBeVisible()
+    await scroller.evaluate((element) => (element.scrollTop = element.scrollHeight))
+    await expect(page.locator('[data-timeline-row="TurnGap"]')).toBeVisible()
+  })
+
+  test("renders comment strips and historical diff summary overflow", async ({ page }) => {
+    const user = userMessage(
+      [
+        userText("The user made the following comment regarding lines 4 through 8 of src/a.ts: Keep this stable", {
+          id: "prt_comment_only",
+          synthetic: true,
+          metadata: {
+            opencodeComment: {
+              path: "src/a.ts",
+              selection: { startLine: 4, startChar: 0, endLine: 8, endChar: 0 },
+              comment: "Keep this stable",
+            },
+          },
+        }),
+        userText("Continue after the comment", { id: "prt_comment_visible" }),
+      ],
+      { summary: { diffs: Array.from({ length: 11 }, (_, index) => summaryDiff(index)) } },
+    )
+    const nextUser = userMessage(undefined, { id: "msg_2000_diff_next_user", created: 1700000010000 })
+    const nextAssistant = assistantMessage([], {
+      id: "msg_2001_diff_next_assistant",
+      parentID: "msg_2000_diff_next_user",
+      created: 1700000011000,
+    })
+    await setupTimeline(page, { messages: [user, assistantMessage(), nextUser, nextAssistant] })
+    const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
+    await scroller.evaluate((element) => (element.scrollTop = 0))
+
+    await expect(page.locator('[data-timeline-row="CommentStrip"]')).toBeVisible()
+    await expect(page.getByText("Keep this stable", { exact: true })).toBeVisible()
+    await expect(page.locator('[data-timeline-row="DiffSummary"]')).toBeVisible()
+    await expect(page.getByText(/show all/i)).toBeVisible()
+  })
+
+  test("renders interruption independently when the turn is not compacted", async ({ page }) => {
+    const user = userMessage()
+    const before = assistantMessage([{ id: "prt_before", type: "text", text: "Before" }], {
+      id: "msg_1001_before",
+      error: { name: "MessageAbortedError", data: { message: "Stopped" } },
+    })
+    const after = assistantMessage([{ id: "prt_after", type: "text", text: "After" }], {
+      id: "msg_1002_after",
+      created: 1700000003000,
+    })
+    await setupTimeline(page, { messages: [user, before, after] })
+
+    await expect(page.getByText("Interrupted", { exact: true })).toBeVisible()
+    const rows = await page
+      .locator('[data-timeline-row="AssistantPart"], [data-timeline-row="TurnDivider"]')
+      .evaluateAll((elements) => elements.map((element) => element.getAttribute("data-timeline-row")))
+    expect(rows).toEqual(["AssistantPart", "TurnDivider", "AssistantPart"])
+  })
+
+  test("renders user image, file attachment, file reference, and agent reference", async ({ page }) => {
+    const text = "Use @explore with @src/a.ts and inspect the attachments"
+    const parts: PartSeed<"user">[] = [
+      userText(text, { id: "prt_user_rich" }),
+      {
+        id: "prt_user_image",
+        type: "file",
+        mime: "image/png",
+        filename: "pixel.png",
+        url: "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+M9QDwADhgGAWjR9awAAAABJRU5ErkJggg==",
+      },
+      {
+        id: "prt_user_attachment",
+        type: "file",
+        mime: "application/json",
+        filename: "tsconfig.json",
+        url: "data:application/json;base64,e30=",
+      },
+      {
+        id: "prt_user_reference",
+        type: "file",
+        mime: "text/plain",
+        filename: "a.ts",
+        url: "src/a.ts",
+        source: { type: "file", path: "src/a.ts", text: { value: "@src/a.ts", start: 18, end: 27 } },
+      },
+      {
+        id: "prt_user_agent",
+        type: "agent",
+        name: "explore",
+        source: { value: "@explore", start: 4, end: 12 },
+      },
+    ]
+    await setupTimeline(page, { messages: [userMessage(parts), assistantMessage()] })
+
+    await expect(page.getByAltText("pixel.png")).toBeVisible()
+    await expect(page.getByText("tsconfig.json")).toBeVisible()
+    await expect(page.getByText("@src/a.ts", { exact: true })).toBeVisible()
+    await expect(page.getByText("@explore", { exact: true })).toBeVisible()
+  })
+})
+
+function editPart(id: string) {
+  return toolPart(
+    id,
+    "edit",
+    "completed",
+    { filePath: "src/a.ts" },
+    {
+      metadata: {
+        filediff: {
+          file: "src/a.ts",
+          additions: 1,
+          deletions: 1,
+          before: "export const value = 1\n",
+          after: "export const value = 2\n",
+        },
+      },
+    },
+  )
+}
+
+function patchPart(id: string) {
+  return toolPart(
+    id,
+    "apply_patch",
+    "completed",
+    { files: ["src/a.ts", "src/b.ts"] },
+    {
+      metadata: {
+        files: [
+          patchFile("src/a.ts", "update"),
+          patchFile("src/b.ts", "add"),
+          patchFile("src/old.ts", "delete"),
+          { ...patchFile("src/moved.ts", "move"), move: "src/new-place.ts" },
+        ],
+      },
+    },
+  )
+}
+
+function patchFile(filePath: string, type: "add" | "update" | "delete" | "move") {
+  return {
+    filePath,
+    relativePath: filePath,
+    type,
+    additions: type === "delete" ? 0 : 1,
+    deletions: type === "add" ? 0 : 1,
+    before: type === "add" ? undefined : "export const before = true\n",
+    after: type === "delete" ? undefined : "export const after = true\n",
+  }
+}
+
+function summaryDiff(index: number) {
+  return {
+    file: `src/diff-${index}.ts`,
+    additions: 1,
+    deletions: 1,
+    patch: `@@ -1 +1 @@\n-export const value = ${index}\n+export const value = ${index + 1}`,
+  }
+}

packages/app/e2e/regression/session-timeline-reasoning-projection.spec.ts

@@ -0,0 +1,93 @@
+import { expect, test } from "@playwright/test"
+import {
+  assistantMessage,
+  reasoningPart,
+  setupTimeline,
+  status,
+  textPart,
+  toolPart,
+  userMessage,
+} from "../performance/timeline-stability/fixture"
+
+const profiles = [
+  { name: "summaries off no reasoning", summaries: false, reasoning: "", other: false, thinking: true, body: false },
+  {
+    name: "summaries off reasoning heading",
+    summaries: false,
+    reasoning: "## Inspecting stability",
+    other: false,
+    thinking: true,
+    body: false,
+  },
+  {
+    name: "summaries off with visible tool",
+    summaries: false,
+    reasoning: "## Inspecting stability",
+    other: true,
+    thinking: true,
+    body: false,
+  },
+  { name: "summaries on no content", summaries: true, reasoning: "", other: false, thinking: true, body: false },
+  {
+    name: "summaries on blank reasoning",
+    summaries: true,
+    reasoning: "   ",
+    other: false,
+    thinking: true,
+    body: false,
+  },
+  {
+    name: "summaries on visible reasoning",
+    summaries: true,
+    reasoning: "## Inspecting stability",
+    other: false,
+    thinking: false,
+    body: true,
+  },
+  {
+    name: "summaries on visible tool no reasoning",
+    summaries: true,
+    reasoning: "",
+    other: true,
+    thinking: false,
+    body: false,
+  },
+] as const
+
+for (const profile of profiles) {
+  test(`projects busy reasoning profile ${profile.name}`, async ({ page }) => {
+    const reasoningID = `prt_reasoning_matrix_${profiles.indexOf(profile)}`
+    const parts = [
+      ...(profile.reasoning ? [reasoningPart(reasoningID, profile.reasoning)] : []),
+      ...(profile.other
+        ? [toolPart(`prt_reasoning_tool_${profiles.indexOf(profile)}`, "skill", "running", { name: "inspect" })]
+        : []),
+    ]
+    const timeline = await setupTimeline(page, {
+      messages: [userMessage(), assistantMessage(parts, { completed: false })],
+      settings: { showReasoningSummaries: profile.summaries },
+    })
+    await timeline.send(status("busy"), 150)
+
+    await expect(page.locator('[data-timeline-row="Thinking"]')).toHaveCount(profile.thinking ? 1 : 0)
+    await expect(page.locator(`[data-timeline-part-id="${reasoningID}"]`)).toHaveCount(profile.body ? 1 : 0)
+    if (!profile.summaries && profile.reasoning.trim()) {
+      await expect(page.getByText("Inspecting stability", { exact: true })).toBeVisible()
+    }
+  })
+}
+
+test("does not infer reasoning visibility from provider identity", async ({ page }) => {
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([textPart("prt_provider_text", "No reasoning payload")], { completed: false }),
+    ],
+    settings: { showReasoningSummaries: true },
+  })
+  await timeline.send(status("busy"), 150)
+
+  await expect(page.locator('[data-timeline-row="Thinking"]')).toHaveCount(0)
+  await expect(page.locator('[data-timeline-part-id*="reasoning"]')).toHaveCount(0)
+  await expect(page.locator('[data-timeline-part-id="prt_provider_text"]')).toBeVisible()
+})

packages/app/e2e/regression/session-timeline-reducer-projection.spec.ts

@@ -0,0 +1,43 @@
+import { expect, test } from "@playwright/test"
+import {
+  assistantMessage,
+  completedAssistantInfo,
+  messageUpdated,
+  partUpdated,
+  setupTimeline,
+  shell,
+  status,
+  textPart,
+  toolPart,
+  userMessage,
+} from "../performance/timeline-stability/fixture"
+
+test("groups singleton and separated context operations at correct boundaries", async ({ page }) => {
+  const parts = [
+    toolPart("prt_boundary_01_read", "read", "completed", { filePath: "src/a.ts" }),
+    textPart("prt_boundary_02_text", "Boundary text"),
+    toolPart("prt_boundary_03_glob", "glob", "completed", { path: ".", pattern: "**/*.ts" }),
+    toolPart("prt_boundary_04_grep", "grep", "completed", { path: ".", pattern: "stable" }),
+    shell("prt_boundary_05_shell", "completed", "done"),
+    toolPart("prt_boundary_06_list", "list", "completed", { path: "src" }),
+  ]
+  await setupTimeline(page, { messages: [userMessage(), assistantMessage(parts)] })
+
+  await expect(page.locator('[data-timeline-part-ids="prt_boundary_01_read"]')).toBeVisible()
+  await expect(page.locator('[data-timeline-part-ids="prt_boundary_03_glob,prt_boundary_04_grep"]')).toBeVisible()
+  await expect(page.locator('[data-timeline-part-ids="prt_boundary_06_list"]')).toBeVisible()
+  await expect(page.locator('[data-timeline-row="AssistantPart"]')).toHaveCount(5)
+})
+
+test("reducer-hardening: converges when idle arrives before final part and message completion", async ({ page }) => {
+  const textID = "prt_event_order_text"
+  const assistant = assistantMessage([textPart(textID, "Partial")], { completed: false })
+  const timeline = await setupTimeline(page, { messages: [userMessage(), assistant] })
+  await timeline.send(status("busy"), 100)
+  await timeline.send(status("idle"), 100)
+  await timeline.send(partUpdated(textPart(textID, "Final after early idle")), 120)
+  await timeline.send(messageUpdated(completedAssistantInfo(assistant.info)), 250)
+
+  await expect(page.locator('[data-timeline-row="Thinking"]')).toHaveCount(0)
+  await expect(page.locator(`[data-timeline-part-id="${textID}"]`)).toContainText("Final after early idle")
+})

packages/app/e2e/regression/session-timeline-tool-projection.spec.ts

@@ -0,0 +1,99 @@
+import { expect, test } from "@playwright/test"
+import {
+  assistantMessage,
+  partUpdated,
+  setupTimeline,
+  toolPart,
+  userMessage,
+} from "../performance/timeline-stability/fixture"
+
+test("renders every tool error outcome without leaking hidden tools", async ({ page }) => {
+  const ordinary = ["bash", "edit", "write", "apply_patch", "webfetch", "websearch", "task", "skill", "mcp_probe"]
+  const parts = ordinary.map((tool, index) =>
+    toolPart(`prt_error_${index}`, tool, "error", errorInput(tool), { error: `${tool} failed visibly` }),
+  )
+  parts.push(
+    toolPart("prt_question_dismissed", "question", "error", questionInput(), {
+      error: "The user dismissed this question",
+    }),
+    toolPart("prt_question_error", "question", "error", questionInput(), { error: "Question transport failed" }),
+    toolPart("prt_todo_error", "todowrite", "error", { todos: [] }, { error: "Hidden todo failure" }),
+  )
+  await setupTimeline(page, { messages: [userMessage(), assistantMessage(parts)] })
+
+  await expect(page.locator('[data-kind="tool-error-card"]')).toHaveCount(ordinary.length + 1)
+  await expect(page.getByText(/dismissed/i)).toBeVisible()
+  await expect(page.locator('[data-timeline-part-id="prt_todo_error"]')).toHaveCount(0)
+  for (let index = 0; index < ordinary.length; index++) {
+    await expect(page.locator(`[data-timeline-part-id="prt_error_${index}"]`)).toBeVisible()
+  }
+})
+
+test("transitions shell and question through running error outcomes", async ({ page }) => {
+  const shellID = "prt_transition_error_shell"
+  const questionID = "prt_transition_error_question"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage(
+        [
+          toolPart(shellID, "bash", "pending", { command: "exit 1" }),
+          toolPart(questionID, "question", "pending", questionInput()),
+        ],
+        { completed: false },
+      ),
+    ],
+  })
+  await timeline.waitForPart(shellID)
+  await expect(page.locator(`[data-timeline-part-id="${questionID}"]`)).toHaveCount(0)
+  await timeline.send(partUpdated(toolPart(shellID, "bash", "running", { command: "exit 1" })), 120)
+  await timeline.send(partUpdated(toolPart(questionID, "question", "running", questionInput())), 180)
+  await expect(page.locator(`[data-timeline-part-id="${questionID}"]`)).toHaveCount(0)
+  await timeline.send(
+    partUpdated(toolPart(shellID, "bash", "error", { command: "exit 1" }, { error: "Command exited 1" })),
+    180,
+  )
+  await timeline.send(
+    partUpdated(
+      toolPart(questionID, "question", "error", questionInput(), { error: "The user dismissed this question" }),
+    ),
+    250,
+  )
+
+  await expect(page.locator(`[data-timeline-part-id="${shellID}"] [data-kind="tool-error-card"]`)).toBeVisible()
+  await expect(page.locator(`[data-timeline-part-id="${questionID}"]`)).toContainText(/dismissed/i)
+})
+
+test("labels all web search provider variants", async ({ page }) => {
+  const parts = [
+    toolPart(
+      "prt_search_parallel",
+      "websearch",
+      "completed",
+      { query: "parallel" },
+      { metadata: { provider: "parallel" } },
+    ),
+    toolPart("prt_search_exa", "websearch", "completed", { query: "exa" }, { metadata: { provider: "exa" } }),
+    toolPart("prt_search_generic", "websearch", "completed", { query: "generic" }),
+  ]
+  await setupTimeline(page, { messages: [userMessage(), assistantMessage(parts)] })
+
+  await expect(page.getByRole("button", { name: /Parallel Web Search/ })).toBeVisible()
+  await expect(page.getByRole("button", { name: /Exa Web Search/ })).toBeVisible()
+  await expect(page.getByRole("button", { name: /^Web Search/ })).toBeVisible()
+})
+
+function questionInput() {
+  return { questions: [{ header: "Stability", question: "Keep it stable?", options: [] }] }
+}
+
+function errorInput(tool: string) {
+  if (tool === "bash") return { command: "exit 1" }
+  if (["edit", "write"].includes(tool)) return { filePath: "src/error.ts", content: "" }
+  if (tool === "apply_patch") return { files: ["src/error.ts"] }
+  if (tool === "webfetch") return { url: "https://example.com" }
+  if (tool === "websearch") return { query: "failure" }
+  if (tool === "task") return { description: "Fail task", subagent_type: "explore" }
+  if (tool === "skill") return { name: "failure" }
+  return { target: "failure" }
+}

packages/app/e2e/regression/session-timeline-tool-state.spec.ts

@@ -0,0 +1,77 @@
+import { expect, test } from "@playwright/test"
+import {
+  assistantMessage,
+  partUpdated,
+  setupTimeline,
+  toolPart,
+  userMessage,
+} from "../performance/timeline-stability/fixture"
+
+test("updates expanded web search links without resetting expansion", async ({ page }) => {
+  const searchID = "prt_websearch_mutation"
+  const input = { query: "timeline stability" }
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([toolPart(searchID, "websearch", "completed", input, { output: "https://example.com/one" })]),
+    ],
+  })
+  const wrapper = page.locator(`[data-timeline-part-id="${searchID}"]`)
+  const trigger = wrapper.locator('[data-slot="collapsible-trigger"]')
+  await trigger.click()
+  await expect(trigger).toHaveAttribute("aria-expanded", "true")
+  await timeline.send(
+    partUpdated(
+      toolPart(searchID, "websearch", "completed", input, {
+        output: "https://example.com/one\nhttps://example.com/two",
+      }),
+    ),
+    300,
+  )
+  await expect(trigger).toHaveAttribute("aria-expanded", "true")
+  await expect(wrapper.locator('a[href="https://example.com/two"]')).toBeVisible()
+})
+
+test("preserves an expanded tool error card across duplicate delivery", async ({ page }) => {
+  const toolID = "prt_duplicate_error"
+  const failed = toolPart(toolID, "bash", "error", { command: "exit 1" }, { error: "Command failed visibly" })
+  const timeline = await setupTimeline(page, { messages: [userMessage(), assistantMessage([failed])] })
+  const wrapper = page.locator(`[data-timeline-part-id="${toolID}"]`)
+  const trigger = wrapper.locator('[data-slot="collapsible-trigger"]')
+  await trigger.click()
+  await expect(trigger).toHaveAttribute("aria-expanded", "true")
+  await timeline.send(partUpdated(failed), 150)
+  await timeline.send(partUpdated(failed), 250)
+  await expect(trigger).toHaveAttribute("aria-expanded", "true")
+  await expect(wrapper).toContainText("Command failed visibly")
+})
+
+test("renders multiple question answers and preserves open state on answer updates", async ({ page }) => {
+  const questionID = "prt_multi_question"
+  const input = {
+    questions: [
+      { header: "First", question: "First choice?", options: [] },
+      { header: "Second", question: "Second choice?", options: [], multiple: true },
+    ],
+  }
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([
+        toolPart(questionID, "question", "completed", input, { metadata: { answers: [["A"], ["B", "C"]] } }),
+      ]),
+    ],
+  })
+  const wrapper = page.locator(`[data-timeline-part-id="${questionID}"]`)
+  const trigger = wrapper.locator('[data-slot="collapsible-trigger"]')
+  await expect(trigger).toHaveAttribute("aria-expanded", "true")
+  await timeline.send(
+    partUpdated(
+      toolPart(questionID, "question", "completed", input, { metadata: { answers: [["Updated"], ["B", "C"]] } }),
+    ),
+    300,
+  )
+  await expect(trigger).toHaveAttribute("aria-expanded", "true")
+  await expect(wrapper).toContainText("Updated")
+  await expect(wrapper).toContainText("B, C")
+})

packages/app/e2e/regression/session-timeline-transport.spec.ts

@@ -0,0 +1,116 @@
+import { expect, test } from "@playwright/test"
+import {
+  assistantMessage,
+  partUpdated,
+  setupTimeline,
+  status,
+  textPart,
+  userMessage,
+} from "../performance/timeline-stability/fixture"
+
+test("keeps one connection open while delivering multiple events", async ({ page }) => {
+  const timeline = await setupTimeline(page)
+
+  const first = await timeline.transport.send(partUpdated(textPart("prt_transport_first", "first event")))
+  const second = await timeline.transport.send(partUpdated(textPart("prt_transport_second", "second event")))
+
+  await timeline.waitForPart("prt_transport_first")
+  await timeline.waitForPart("prt_transport_second")
+  expect(first.connectionID).toBe(second.connectionID)
+  expect(await timeline.transport.connections()).toHaveLength(1)
+  expect(await timeline.transport.acknowledgements()).toHaveLength(2)
+})
+
+test("delivers a burst from one stream chunk", async ({ page }) => {
+  const timeline = await setupTimeline(page)
+  const acknowledgements = await timeline.transport.burst([
+    partUpdated(textPart("prt_transport_burst_a", "burst a")),
+    partUpdated(textPart("prt_transport_burst_b", "burst b")),
+  ])
+
+  await timeline.waitForPart("prt_transport_burst_a")
+  await timeline.waitForPart("prt_transport_burst_b")
+  expect(acknowledgements.map((item) => item.chunkCount)).toEqual([1, 1])
+  expect(new Set(acknowledgements.map((item) => item.deliveryID)).size).toBe(2)
+})
+
+test("parses split JSON and a split multibyte code point", async ({ page }) => {
+  const timeline = await setupTimeline(page)
+  const payload = partUpdated(textPart("prt_transport_split", "split snowman \u2603\u2603\u2603"))
+  const encoded = new TextEncoder().encode(`data: ${JSON.stringify(payload)}\n\n`)
+  const snowman = new TextEncoder().encode("\u2603")[0]!
+  const multibyte = encoded.indexOf(snowman)
+
+  const acknowledgement = await timeline.transport.split(payload, [9, multibyte + 1, multibyte + 2])
+
+  await timeline.waitForPart("prt_transport_split")
+  await expect(page.locator('[data-timeline-part-id="prt_transport_split"]')).toContainText(
+    "split snowman \u2603\u2603\u2603",
+  )
+  expect(acknowledgement.chunkCount).toBe(4)
+})
+
+test("delivers server heartbeat without mutating the timeline", async ({ page }) => {
+  const timeline = await setupTimeline(page, {
+    messages: [userMessage(), assistantMessage([textPart("prt_transport_steady", "steady")])],
+  })
+  const before = await page.locator("[data-timeline-row]").allTextContents()
+
+  await timeline.transport.heartbeat()
+  await timeline.settle()
+
+  expect(await page.locator("[data-timeline-row]").allTextContents()).toEqual(before)
+  expect(await timeline.transport.connections()).toHaveLength(1)
+})
+
+test("reconnects after a clean close", async ({ page }) => {
+  const timeline = await setupTimeline(page, { eventRetry: 10 })
+  const first = await timeline.transport.waitForConnection()
+
+  await timeline.transport.close()
+  const second = await timeline.transport.waitForConnection({ after: first.id })
+  await timeline.transport.send(partUpdated(textPart("prt_transport_close", "after close")))
+
+  await timeline.waitForPart("prt_transport_close")
+  expect(second.id).toBeGreaterThan(first.id)
+  expect((await timeline.transport.connections())[0]?.endedBy).toBe("close")
+})
+
+test("reconnects after a stream error", async ({ page }) => {
+  const timeline = await setupTimeline(page, { eventRetry: 10 })
+  const first = await timeline.transport.waitForConnection()
+
+  await timeline.transport.error("contract failure")
+  const second = await timeline.transport.waitForConnection({ after: first.id })
+  await timeline.transport.send(status("busy"))
+
+  await expect.poll(async () => (await timeline.transport.connections()).length).toBe(2)
+  expect(second.id).toBeGreaterThan(first.id)
+  expect((await timeline.transport.connections())[0]?.endedBy).toBe("error")
+})
+
+test("records event IDs and reconnect Last-Event-ID headers", async ({ page }) => {
+  const timeline = await setupTimeline(page, { eventRetry: 10 })
+  const first = await timeline.transport.send(partUpdated(textPart("prt_transport_id", "event with id")), {
+    id: "timeline-event-7",
+  })
+  await timeline.waitForPart("prt_transport_id")
+
+  await timeline.transport.error("retry with event id")
+  const connection = await timeline.transport.waitForConnection({ after: first.connectionID })
+
+  expect(first.eventID).toBe("timeline-event-7")
+  expect(connection.headers["last-event-id"]).toBe("timeline-event-7")
+})
+
+test("passes through non-event fetches", async ({ page }) => {
+  const timeline = await setupTimeline(page)
+
+  const health = await page.evaluate(async () => {
+    const response = await fetch("/global/health")
+    return response.json()
+  })
+
+  expect(health).toEqual({ healthy: true })
+  expect(await timeline.transport.connections()).toHaveLength(1)
+})

packages/app/e2e/regression/session-todo-dock-navigation.spec.ts

@@ -0,0 +1,186 @@
+import { base64Encode } from "@opencode-ai/core/util/encode"
+import { expect, test, type Page } from "@playwright/test"
+import { mockOpenCodeServer } from "../utils/mock-server"
+import { expectSessionTitle } from "../utils/waits"
+
+const directory = "C:/OpenCode/TodoDockNavigation"
+const projectID = "proj_todo_dock_navigation"
+const sourceID = "ses_todo_dock_source"
+const otherID = "ses_todo_dock_other"
+const sourceTitle = "Todo dock animation"
+const otherTitle = "Separate session"
+
+const activeTodos = [
+  { id: "todo-1", content: "Receive todos in the active session", status: "completed", priority: "high" },
+  { id: "todo-2", content: "Keep the dock visible across tabs", status: "completed", priority: "high" },
+  { id: "todo-3", content: "Close after the final todo", status: "in_progress", priority: "high" },
+]
+
+type EventPayload = {
+  directory: string
+  payload: Record<string, unknown>
+}
+
+test.use({ viewport: { width: 1440, height: 900 }, reducedMotion: "no-preference" })
+
+test("animates todo lifecycle without replaying it across session tabs", async ({ page }) => {
+  test.setTimeout(90_000)
+  const events: EventPayload[] = []
+  const todos: Record<string, typeof activeTodos> = { [sourceID]: [], [otherID]: [] }
+
+  await mockOpenCodeServer(page, {
+    directory,
+    project: {
+      id: projectID,
+      worktree: directory,
+      vcs: "git",
+      name: "todo-dock-navigation",
+      time: { created: 1700000000000, updated: 1700000000000 },
+      sandboxes: [],
+    },
+    provider: {
+      all: [
+        {
+          id: "opencode",
+          name: "OpenCode",
+          models: {
+            "claude-opus-4-6": {
+              id: "claude-opus-4-6",
+              name: "Claude Opus 4.6",
+              limit: { context: 200_000 },
+            },
+          },
+        },
+      ],
+      connected: ["opencode"],
+      default: { providerID: "opencode", modelID: "claude-opus-4-6" },
+    },
+    sessions: [session(sourceID, sourceTitle, 1700000000000), session(otherID, otherTitle, 1700000001000)],
+    pageMessages: () => ({ items: [] }),
+    events: () => events.splice(0, 1),
+    eventRetry: 16,
+    todos: (sessionID) => todos[sessionID] ?? [],
+  })
+  await configurePage(page)
+
+  await page.goto(sessionHref(sourceID))
+  await expectSessionTitle(page, sourceTitle)
+  const dock = page.locator('[data-component="session-todo-dock"]')
+  await expect(dock).toHaveCount(0)
+
+  events.push(statusEvent(sourceID, "busy"))
+  await expect(page.getByRole("button", { name: "Stop" })).toBeVisible()
+
+  await page.waitForTimeout(700)
+  const opening = sampleDock(page, 1_000)
+  todos[sourceID] = activeTodos
+  events.push(todoEvent(sourceID, activeTodos))
+  await expect(dock).toBeVisible()
+  await expect(dock.locator('[data-state="in_progress"]')).toHaveCount(1)
+  expect((await opening).some((sample) => sample.opacity > 0.05 && sample.opacity < 0.95)).toBe(true)
+
+  await switchSession(page, otherID, otherTitle)
+  await expect(dock).toHaveCount(0)
+
+  const returningOpen = sampleDock(page, 700)
+  await switchSession(page, sourceID, sourceTitle)
+  const openSamples = (await returningOpen).filter((sample) => sample.present)
+  expect(openSamples.length).toBeGreaterThan(0)
+  expect(openSamples[0]!.opacity).toBeGreaterThan(0.98)
+  expect(openSamples[0]!.height).toBeGreaterThan(70)
+  await expect(dock.locator('[data-state="in_progress"]')).toHaveCount(1)
+
+  const completedTodos = activeTodos.map((todo) => ({ ...todo, status: "completed" }))
+  const closing = sampleDock(page, 1_000)
+  todos[sourceID] = completedTodos
+  events.push(todoEvent(sourceID, completedTodos))
+  await expect(dock).toHaveCount(0)
+  expect((await closing).some((sample) => sample.opacity > 0.05 && sample.opacity < 0.95)).toBe(true)
+  todos[sourceID] = []
+  events.push(todoEvent(sourceID, []))
+
+  await switchSession(page, otherID, otherTitle)
+  const returningEmpty = sampleDock(page, 700)
+  await switchSession(page, sourceID, sourceTitle)
+  await expect(dock).toHaveCount(0)
+  expect((await returningEmpty).every((sample) => !sample.present)).toBe(true)
+})
+
+function session(id: string, title: string, created: number) {
+  return {
+    id,
+    slug: id,
+    projectID,
+    directory,
+    title,
+    version: "dev",
+    time: { created, updated: created },
+  }
+}
+
+function statusEvent(sessionID: string, type: "busy" | "idle"): EventPayload {
+  return {
+    directory,
+    payload: { type: "session.status", properties: { sessionID, status: { type } } },
+  }
+}
+
+function todoEvent(sessionID: string, next: typeof activeTodos): EventPayload {
+  return {
+    directory,
+    payload: { type: "todo.updated", properties: { sessionID, todos: next } },
+  }
+}
+
+async function configurePage(page: Page) {
+  const server = `http://${process.env.PLAYWRIGHT_SERVER_HOST ?? "127.0.0.1"}:${process.env.PLAYWRIGHT_SERVER_PORT ?? "4096"}`
+  await page.addInitScript(
+    ({ directory, dirBase64, server, sessionIDs }) => {
+      localStorage.setItem("settings.v3", JSON.stringify({ general: { newLayoutDesigns: true } }))
+      localStorage.setItem(
+        "opencode.global.dat:server",
+        JSON.stringify({
+          projects: { local: [{ worktree: directory, expanded: true }] },
+          lastProject: { local: directory },
+        }),
+      )
+      localStorage.setItem(
+        "opencode.window.browser.dat:tabs",
+        JSON.stringify(sessionIDs.map((sessionId) => ({ type: "session", server, dirBase64, sessionId }))),
+      )
+    },
+    { directory, dirBase64: base64Encode(directory), server, sessionIDs: [sourceID, otherID] },
+  )
+}
+
+function sessionHref(sessionID: string) {
+  const server = `http://${process.env.PLAYWRIGHT_SERVER_HOST ?? "127.0.0.1"}:${process.env.PLAYWRIGHT_SERVER_PORT ?? "4096"}`
+  return `/server/${base64Encode(server)}/session/${sessionID}`
+}
+
+async function switchSession(page: Page, sessionID: string, title: string) {
+  const href = sessionHref(sessionID)
+  const tab = page.locator(`[data-slot="titlebar-tabs"] a[href="${href}"]`).first()
+  await expect(tab).toBeVisible()
+  await tab.click()
+  await expectSessionTitle(page, title)
+}
+
+function sampleDock(page: Page, duration: number) {
+  return page.evaluate(async (duration) => {
+    const samples: { present: boolean; height: number; opacity: number }[] = []
+    const start = performance.now()
+    while (performance.now() - start < duration) {
+      const dock = document.querySelector<HTMLElement>('[data-component="session-todo-dock"]')
+      const clip = dock?.parentElement?.parentElement
+      const label = dock?.querySelector<HTMLElement>('[data-action="session-todo-toggle"] span[aria-label]')
+      samples.push({
+        present: !!dock,
+        height: clip?.getBoundingClientRect().height ?? 0,
+        opacity: label ? Number.parseFloat(getComputedStyle(label).opacity) : 0,
+      })
+      await new Promise(requestAnimationFrame)
+    }
+    return samples
+  }, duration)
+}

packages/app/e2e/regression/subagent-child-navigation.spec.ts

@@ -0,0 +1,200 @@
+import { base64Encode } from "@opencode-ai/core/util/encode"
+import { expect, test, type Page } from "@playwright/test"
+import { mockOpenCodeServer } from "../utils/mock-server"
+import { expectSessionTitle } from "../utils/waits"
+
+const directory = "C:/OpenCode/SubagentNavigation"
+const projectID = "proj_subagent_navigation"
+const parentID = "ses_subagent_parent"
+const childID = "ses_subagent_child"
+const parentTitle = "Parent session"
+const childTitle = "Subagent child session"
+// Child session pages derive their heading from the task part that spawned them.
+const taskDescription = "Inspect child navigation"
+
+type EventPayload = { directory: string; payload: Record<string, unknown> }
+
+test.use({ viewport: { width: 1440, height: 900 } })
+
+test("navigates to a subagent child session missing from the session list", async ({ page }) => {
+  await setup(page)
+  await openChildFromParent(page)
+
+  await expectSessionTitle(page, taskDescription)
+  await expect(page.getByRole("heading", { name: parentTitle })).toHaveCount(0)
+
+  const titlebarRight = page.locator("#opencode-titlebar-right")
+  await expect(titlebarRight.getByRole("button", { name: "Toggle review" })).toHaveCount(1)
+})
+
+test("shows the not found fallback when the viewed session is deleted", async ({ page }) => {
+  const events: EventPayload[] = []
+  await setup(page, () => events.splice(0, 1))
+  await openChildFromParent(page)
+  await expectSessionTitle(page, taskDescription)
+
+  events.push({
+    directory,
+    payload: { type: "session.deleted", properties: { info: childSession() } },
+  })
+
+  await expect(page.getByText("This session cannot be found")).toBeVisible()
+  await expect(page.getByRole("button", { name: "Close Tab" })).toBeVisible()
+  await expect(page.getByRole("heading", { name: taskDescription })).toHaveCount(0)
+})
+
+async function setup(page: Page, events?: () => EventPayload[]) {
+  await mockOpenCodeServer(page, {
+    directory,
+    project: {
+      id: projectID,
+      worktree: directory,
+      vcs: "git",
+      name: "subagent-navigation",
+      time: { created: 1700000000000, updated: 1700000000000 },
+      sandboxes: [],
+    },
+    provider: {
+      all: [
+        {
+          id: "opencode",
+          name: "OpenCode",
+          models: {
+            "claude-opus-4-6": { id: "claude-opus-4-6", name: "Claude Opus 4.6", limit: { context: 200_000 } },
+          },
+        },
+      ],
+      connected: ["opencode"],
+      default: { providerID: "opencode", modelID: "claude-opus-4-6" },
+    },
+    sessions: [session(parentID, parentTitle, 1700000000000), childSession()],
+    pageMessages: (sessionID) => ({ items: sessionID === parentID ? parentMessages() : [] }),
+    events,
+    eventRetry: events ? 16 : undefined,
+  })
+  // The child session resolves via /session/:id but is absent from the /session list,
+  // matching a subagent session that has not been loaded into the list cache yet.
+  await page.route(
+    (url) => url.pathname === "/session" && url.port === (process.env.PLAYWRIGHT_SERVER_PORT ?? "4096"),
+    (route) =>
+      route.fulfill({
+        status: 200,
+        contentType: "application/json",
+        headers: { "access-control-allow-origin": "*" },
+        body: JSON.stringify([session(parentID, parentTitle, 1700000000000)]),
+      }),
+  )
+  await configurePage(page)
+}
+
+async function openChildFromParent(page: Page) {
+  await page.goto(sessionHref(parentID))
+  await expectSessionTitle(page, parentTitle)
+
+  const card = page.locator(`a[href="${sessionHref(childID)}"]`)
+  await expect(card).toBeVisible()
+  await card.click()
+
+  await expect(page).toHaveURL(new RegExp(`/server/.+/session/${childID}$`), { timeout: 15_000 })
+}
+
+function session(id: string, title: string, created: number, extra?: Record<string, unknown>) {
+  return {
+    id,
+    slug: id,
+    projectID,
+    directory,
+    title,
+    version: "dev",
+    time: { created, updated: created },
+    ...extra,
+  }
+}
+
+function childSession() {
+  return session(childID, childTitle, 1700000001000, { parentID })
+}
+
+function parentMessages() {
+  const userID = "msg_user_0001"
+  const assistantID = "msg_assistant_0001"
+  return [
+    {
+      info: {
+        id: userID,
+        sessionID: parentID,
+        role: "user",
+        time: { created: 1700000000000 },
+        agent: "build",
+        model: { providerID: "opencode", modelID: "claude-opus-4-6" },
+      },
+      parts: [
+        {
+          id: "prt_user_text_0001",
+          sessionID: parentID,
+          messageID: userID,
+          type: "text",
+          text: "Delegate work to a subagent",
+        },
+      ],
+    },
+    {
+      info: {
+        id: assistantID,
+        sessionID: parentID,
+        role: "assistant",
+        time: { created: 1700000001000, completed: 1700000002000 },
+        parentID: userID,
+        modelID: "claude-opus-4-6",
+        providerID: "opencode",
+        mode: "build",
+        agent: "build",
+        path: { cwd: directory, root: directory },
+        cost: 0.01,
+        tokens: { input: 100, output: 200, reasoning: 0, cache: { read: 0, write: 0 } },
+        finish: "stop",
+      },
+      parts: [
+        {
+          id: "prt_tool_task_0001",
+          sessionID: parentID,
+          messageID: assistantID,
+          type: "tool",
+          callID: "call_task_0001",
+          tool: "task",
+          state: {
+            status: "completed",
+            input: { description: taskDescription, subagent_type: "explore" },
+            output: "Subagent finished",
+            title: taskDescription,
+            metadata: { sessionId: childID },
+            time: { start: 1700000001000, end: 1700000002000 },
+          },
+        },
+      ],
+    },
+  ]
+}
+
+async function configurePage(page: Page) {
+  const server = `http://${process.env.PLAYWRIGHT_SERVER_HOST ?? "127.0.0.1"}:${process.env.PLAYWRIGHT_SERVER_PORT ?? "4096"}`
+  await page.addInitScript(
+    ({ directory, server, sessionId }) => {
+      localStorage.setItem("settings.v3", JSON.stringify({ general: { newLayoutDesigns: true } }))
+      localStorage.setItem(
+        "opencode.global.dat:server",
+        JSON.stringify({
+          projects: { local: [{ worktree: directory, expanded: true }] },
+          lastProject: { local: directory },
+        }),
+      )
+      localStorage.setItem("opencode.window.browser.dat:tabs", JSON.stringify([{ type: "session", server, sessionId }]))
+    },
+    { directory, server, sessionId: parentID },
+  )
+}
+
+function sessionHref(sessionID: string) {
+  const server = `http://${process.env.PLAYWRIGHT_SERVER_HOST ?? "127.0.0.1"}:${process.env.PLAYWRIGHT_SERVER_PORT ?? "4096"}`
+  return `/server/${base64Encode(server)}/session/${sessionID}`
+}

packages/app/e2e/regression/tab-navigate-mousedown.spec.ts

@@ -0,0 +1,108 @@
+import { expect, test, type Page, type Route } from "@playwright/test"
+import { base64Encode } from "@opencode-ai/core/util/encode"
+
+const server = "http://127.0.0.1:4096"
+const sessionA = session("ses_tab_a", "Tab A session")
+const sessionB = session("ses_tab_b", "Tab B session")
+
+test("pressing mouse down on a tab navigates before mouse up", async ({ page }) => {
+  await mockServer(page)
+  await page.addInitScript(
+    ({ server, sessionA, sessionB }) => {
+      localStorage.setItem("settings.v3", JSON.stringify({ general: { newLayoutDesigns: true } }))
+      localStorage.setItem(
+        "opencode.window.browser.dat:tabs",
+        JSON.stringify([
+          { type: "session", server, sessionId: sessionA },
+          { type: "session", server, sessionId: sessionB },
+        ]),
+      )
+    },
+    { server, sessionA: sessionA.id, sessionB: sessionB.id },
+  )
+
+  const hrefA = `/server/${base64Encode(server)}/session/${sessionA.id}`
+  const hrefB = `/server/${base64Encode(server)}/session/${sessionB.id}`
+  await page.goto(hrefA)
+  await expect(page.getByText(sessionA.title).first()).toBeVisible()
+
+  const linkB = page.locator(`a[data-titlebar-tab-link][href="${hrefB}"]`)
+  await expect(linkB).toBeVisible()
+  const box = await linkB.boundingBox()
+  if (!box) throw new Error("tab link has no bounding box")
+  await page.mouse.move(box.x + box.width / 2, box.y + box.height / 2)
+  await page.mouse.down()
+
+  // Navigation must happen on mousedown, before the button is released.
+  await expect(page).toHaveURL(new RegExp(`${hrefB.replace(/[.*+?^${}()|[\]\\]/g, "\\$&")}$`))
+  await page.mouse.up()
+  await expect(page).toHaveURL(new RegExp(`${hrefB.replace(/[.*+?^${}()|[\]\\]/g, "\\$&")}$`))
+})
+
+function session(id: string, title: string) {
+  return {
+    id,
+    slug: id,
+    projectID: "project-tabs",
+    directory: "C:/tab-project",
+    title,
+    version: "dev",
+    time: { created: 1, updated: 1 },
+  }
+}
+
+async function mockServer(page: Page) {
+  const sessions = [sessionA, sessionB]
+  await page.route("**/*", async (route) => {
+    const url = new URL(route.request().url())
+    if (url.origin !== server) return route.fallback()
+    if (url.pathname === "/global/event" || url.pathname === "/event") return sse(route)
+    if (url.pathname === "/global/health") return json(route, { healthy: true })
+    if (url.pathname === "/session") return json(route, sessions)
+    const byId = sessions.find((item) => url.pathname === `/session/${item.id}`)
+    if (byId) return json(route, byId)
+    if (/^\/session\/[^/]+$/.test(url.pathname)) return json(route, { name: "NotFoundError" }, 404)
+    if (/^\/session\/[^/]+\/message$/.test(url.pathname)) return json(route, [])
+    if (/^\/session\/[^/]+\/(children|todo|diff)$/.test(url.pathname)) return json(route, [])
+    if (["/skill", "/command", "/lsp", "/formatter", "/permission", "/question", "/vcs/diff"].includes(url.pathname))
+      return json(route, [])
+    if (["/global/config", "/config", "/provider/auth", "/mcp", "/session/status"].includes(url.pathname))
+      return json(route, {})
+    if (url.pathname === "/provider")
+      return json(route, { all: [], connected: [], default: { providerID: "", modelID: "" } })
+    if (url.pathname === "/agent") return json(route, [{ name: "build", mode: "primary" }])
+    if (url.pathname === "/project" || url.pathname === "/project/current") {
+      const project = {
+        id: sessionA.projectID,
+        worktree: sessionA.directory,
+        vcs: "git",
+        time: { created: 1, updated: 1 },
+        sandboxes: [],
+      }
+      return json(route, url.pathname === "/project" ? [project] : project)
+    }
+    if (url.pathname === "/path")
+      return json(route, {
+        state: sessionA.directory,
+        config: sessionA.directory,
+        worktree: sessionA.directory,
+        directory: sessionA.directory,
+        home: sessionA.directory,
+      })
+    if (url.pathname === "/vcs") return json(route, { branch: "main", default_branch: "main" })
+    return json(route, {})
+  })
+}
+
+function json(route: Route, body: unknown, status = 200) {
+  return route.fulfill({
+    status,
+    contentType: "application/json",
+    headers: { "access-control-allow-origin": "*" },
+    body: JSON.stringify(body),
+  })
+}
+
+function sse(route: Route) {
+  return route.fulfill({ status: 200, contentType: "text/event-stream", body: ": ok\n\n" })
+}

packages/app/e2e/regression/terminal-hidden.spec.ts

@@ -0,0 +1,79 @@
+import { expect, test } from "@playwright/test"
+import { mockOpenCodeServer } from "../utils/mock-server"
+import { expectSessionTitle } from "../utils/waits"
+
+const directory = "C:/OpenCode/HiddenTerminalRegression"
+const projectID = "proj_hidden_terminal_regression"
+const sessionID = "ses_hidden_terminal_regression"
+const title = "Hidden terminal regression"
+
+test("unmounts the terminal renderer while the pane is hidden", async ({ page }) => {
+  await page.setViewportSize({ width: 1400, height: 900 })
+  await mockOpenCodeServer(page, {
+    directory,
+    project: {
+      id: projectID,
+      worktree: directory,
+      vcs: "git",
+      name: "hidden-terminal-regression",
+      time: { created: 1700000000000, updated: 1700000000000 },
+      sandboxes: [],
+    },
+    provider: {
+      all: [
+        {
+          id: "opencode",
+          name: "OpenCode",
+          models: { test: { id: "test", name: "Test", limit: { context: 200_000 } } },
+        },
+      ],
+      connected: ["opencode"],
+      default: { providerID: "opencode", modelID: "test" },
+    },
+    sessions: [
+      {
+        id: sessionID,
+        slug: "hidden-terminal-regression",
+        projectID,
+        directory,
+        title,
+        version: "dev",
+        time: { created: 1700000000000, updated: 1700000000000 },
+      },
+    ],
+    pageMessages: () => ({ items: [] }),
+  })
+  await page.route("**/pty", (route) =>
+    route.fulfill({
+      status: 200,
+      contentType: "application/json",
+      body: JSON.stringify({ id: "pty_hidden_terminal", title: "Terminal 1" }),
+    }),
+  )
+  await page.route("**/pty/pty_hidden_terminal", (route) =>
+    route.fulfill({ status: 200, contentType: "application/json", body: "{}" }),
+  )
+  await page.routeWebSocket("**/pty/pty_hidden_terminal/connect", () => undefined)
+
+  await page.goto(`/${base64Encode(directory)}/session/${sessionID}`)
+  await expectSessionTitle(page, title)
+
+  await page.keyboard.press("Control+Backquote")
+  const panel = page.locator("#terminal-panel")
+  await expect(panel).toHaveAttribute("aria-hidden", "false")
+  await expect(page.locator('[data-component="terminal"]')).toBeVisible()
+
+  await page.keyboard.press("Control+Backquote")
+  await expect(panel).toHaveAttribute("aria-hidden", "true")
+  await expect(page.locator('[data-component="terminal"]')).toHaveCount(0)
+
+  await page.setViewportSize({ width: 1200, height: 700 })
+  await expect(page.locator('[data-component="terminal"]')).toHaveCount(0)
+
+  await page.keyboard.press("Control+Backquote")
+  await expect(page.locator('[data-component="terminal"]')).toBeVisible()
+})
+
+function base64Encode(value: string) {
+  return Buffer.from(value, "utf8").toString("base64").replace(/\+/g, "-").replace(/\//g, "_").replace(/=/g, "")
+}

packages/app/e2e/regression/terminal-tab-switch.spec.ts

@@ -0,0 +1,145 @@
+import { base64Encode } from "@opencode-ai/core/util/encode"
+import { expect, test, type Page } from "@playwright/test"
+import { mockOpenCodeServer } from "../utils/mock-server"
+import { expectSessionTitle } from "../utils/waits"
+
+const directory = "C:/OpenCode/TerminalTabSwitch"
+const projectID = "proj_terminal_tab_switch"
+const sessionA = "ses_terminal_tab_a"
+const sessionB = "ses_terminal_tab_b"
+const titleA = "Alpha session"
+const titleB = "Beta session"
+const ptyID = "pty_tab_switch"
+const server = `http://${process.env.PLAYWRIGHT_SERVER_HOST ?? "127.0.0.1"}:${process.env.PLAYWRIGHT_SERVER_PORT ?? "4096"}`
+// Marks the terminal DOM node so a remount (fresh node) is detectable.
+const PROBE = "original"
+
+test.use({ viewport: { width: 1440, height: 900 } })
+
+// Terminals are workspace-scoped: switching between session tabs in the same
+// workspace must keep the terminal mounted and its PTY connection open instead
+// of tearing it down and reconnecting.
+test("keeps the terminal session alive when switching session tabs in a workspace", async ({ page }) => {
+  const connections = await setup(page)
+
+  await page.goto(sessionHref(sessionA))
+  await expectSessionTitle(page, titleA)
+
+  await page.keyboard.press("Control+Backquote")
+  const terminal = page.locator('[data-component="terminal"]')
+  await expect(terminal).toBeVisible()
+  await expect.poll(() => connections.length).toBe(1)
+  await writeProbe(page)
+
+  await switchTab(page, titleB)
+  await expectSessionTitle(page, titleB)
+  await expect(terminal).toBeVisible()
+  expect(await readProbe(page)).toBe(PROBE)
+  expect(connections.length).toBe(1)
+
+  await switchTab(page, titleA)
+  await expectSessionTitle(page, titleA)
+  await expect(terminal).toBeVisible()
+  expect(await readProbe(page)).toBe(PROBE)
+  expect(connections.length).toBe(1)
+})
+
+type Probed = HTMLElement & { __e2eProbe?: string }
+
+async function switchTab(page: Page, title: string) {
+  await page.locator("[data-titlebar-tab-slot]", { hasText: title }).click()
+}
+
+async function writeProbe(page: Page) {
+  await page.locator('[data-component="terminal"]').evaluate((el, probe) => {
+    ;(el as Probed).__e2eProbe = probe
+  }, PROBE)
+}
+
+async function readProbe(page: Page) {
+  return page.locator('[data-component="terminal"]').evaluate((el) => (el as Probed).__e2eProbe)
+}
+
+async function setup(page: Page) {
+  await mockOpenCodeServer(page, {
+    directory,
+    project: {
+      id: projectID,
+      worktree: directory,
+      vcs: "git",
+      name: "terminal-tab-switch",
+      time: { created: 1700000000000, updated: 1700000000000 },
+      sandboxes: [],
+    },
+    provider: {
+      all: [
+        {
+          id: "opencode",
+          name: "OpenCode",
+          models: { test: { id: "test", name: "Test", limit: { context: 200_000 } } },
+        },
+      ],
+      connected: ["opencode"],
+      default: { providerID: "opencode", modelID: "test" },
+    },
+    sessions: [session(sessionA, titleA, 1700000000000), session(sessionB, titleB, 1700000001000)],
+    pageMessages: () => ({ items: [] }),
+  })
+  await page.route("**/pty", (route) =>
+    route.fulfill({
+      status: 200,
+      contentType: "application/json",
+      body: JSON.stringify({ id: ptyID, title: "Terminal 1" }),
+    }),
+  )
+  await page.route(`**/pty/${ptyID}`, (route) =>
+    route.fulfill({ status: 200, contentType: "application/json", body: "{}" }),
+  )
+  await page.route(`**/pty/${ptyID}/connect-token*`, (route) =>
+    route.fulfill({
+      status: 200,
+      contentType: "application/json",
+      headers: { "access-control-allow-origin": "*" },
+      body: JSON.stringify({ ticket: "e2e-ticket" }),
+    }),
+  )
+  const connections: string[] = []
+  await page.routeWebSocket(new RegExp(`/pty/${ptyID}/connect`), (ws) => {
+    connections.push(ws.url())
+  })
+
+  await page.addInitScript(
+    ({ directory, server, sessions }) => {
+      localStorage.setItem("settings.v3", JSON.stringify({ general: { newLayoutDesigns: true } }))
+      localStorage.setItem(
+        "opencode.global.dat:server",
+        JSON.stringify({
+          projects: { local: [{ worktree: directory, expanded: true }] },
+          lastProject: { local: directory },
+        }),
+      )
+      localStorage.setItem(
+        "opencode.window.browser.dat:tabs",
+        JSON.stringify(sessions.map((sessionId: string) => ({ type: "session", server, sessionId }))),
+      )
+    },
+    { directory, server, sessions: [sessionA, sessionB] },
+  )
+  return connections
+}
+
+function session(id: string, title: string, created: number) {
+  return {
+    id,
+    slug: id,
+    projectID,
+    directory,
+    title,
+    version: "dev",
+    time: { created, updated: created },
+  }
+}
+
+function sessionHref(sessionID: string) {
+  return `/server/${base64Encode(server)}/session/${sessionID}`
+}

packages/app/e2e/smoke/session-timeline.fixture.ts

@@ -21,6 +21,7 @@ const words = [
   "vector",
 ]
 
+const serverKey = "http://127.0.0.1:4096"
 const sourceID = "ses_smoke_source"
 const targetID = "ses_smoke_target"
 const directory = "C:/OpenCode/SmokeProject"
@@ -139,7 +140,7 @@ function toolPart(
       status: "completed",
       input,
       output: lorem(index * 23 + partIndex, outputLength),
-      title: tool === "bash" ? "Verify generated output" : input.filePath || input.path || input.pattern || "completed",
+      title: tool === "bash" ? input.command : input.filePath || input.path || input.pattern || "completed",
       metadata,
       time: { start: 1700000000000 + index * 10_000, end: 1700000000000 + index * 10_000 + 400 },
     },
@@ -200,9 +201,7 @@ function turn(index: number): Message[] {
     ...(index % 8 === 0
       ? [toolPart(index, 8, "apply_patch", { files: [`src/generated/patch-${index}.ts`] }, 620)]
       : []),
-    ...(index % 7 === 0
-      ? [toolPart(index, 4, "bash", { command: "bun typecheck", description: "Verify generated output" }, 620)]
-      : []),
+    ...(index % 7 === 0 ? [toolPart(index, 4, "bash", { command: "bun typecheck" }, 620)] : []),
     ...(index % 10 === 0 ? [toolPart(index, 9, "webfetch", { url: "https://example.com/docs/sample" }, 120)] : []),
     ...(index % 11 === 0 ? [toolPart(index, 10, "websearch", { query: "sample movement notes" }, 240)] : []),
     ...(index % 13 === 0
@@ -242,6 +241,7 @@ function orderedParts(message: Message) {
 
 export const fixture = {
   directory,
+  serverKey,
   project: {
     id: projectID,
     worktree: directory,
@@ -295,6 +295,7 @@ export const fixture = {
         .filter(renderable)
         .map((part) => part.id),
     ),
+    expandedShellPartID: targetMessages.flatMap((message) => message.parts).find((part) => part.tool === "bash")!.id,
   },
 }
 

packages/app/e2e/smoke/session-timeline.spec.ts

@@ -58,7 +58,18 @@ test.describe("smoke: session timeline", () => {
       await page.mouse.wheel(0, -120)
       await page.waitForTimeout(20)
     }
-    const keys = ["prt_user_text_smoke_0032", "prt_text_2_smoke_0032", "prt_tool_apply_patch_8_smoke_0032"]
+    const keys = await scroller.evaluate((element) => {
+      const view = element.getBoundingClientRect()
+      return [...element.querySelectorAll<HTMLElement>("[data-timeline-part-id]")]
+        .filter((row) => {
+          const rect = row.getBoundingClientRect()
+          return rect.bottom > view.top && rect.top < view.bottom
+        })
+        .map((row) => row.dataset.timelinePartId)
+        .filter((id): id is string => !!id)
+        .slice(0, 3)
+    })
+    expect(keys.length).toBeGreaterThan(0)
     const positions = () =>
       scroller.evaluate((element, keys) => {
         const top = element.getBoundingClientRect().top
@@ -116,7 +127,7 @@ test.describe("smoke: session timeline", () => {
     await page.addInitScript(
       ({ dirBase64, sourceID, targetID }) => {
         localStorage.setItem(
-          "opencode.global.dat:tabs",
+          "opencode.window.browser.dat:tabs",
           JSON.stringify(
             [sourceID, targetID].map((sessionId) => ({
               type: "session",
@@ -242,7 +253,7 @@ test.describe("smoke: session timeline", () => {
     await page.addInitScript(
       ({ dirBase64, sourceID, targetID }) => {
         localStorage.setItem(
-          "opencode.global.dat:tabs",
+          "opencode.window.browser.dat:tabs",
           JSON.stringify(
             [sourceID, targetID].map((sessionId) => ({
               type: "session",
@@ -327,6 +338,18 @@ test.describe("smoke: session timeline", () => {
     const expectedMessageIDs = fixture.expected.targetMessageIDs
     await expectSessionTimelineReady(page, expectedPartIDs, expectedMessageIDs, errors)
     await expectCanScrollToStart(page, expectedPartIDs, expectedMessageIDs, errors)
+
+    const shell = page.locator(`[data-timeline-part-id="${fixture.expected.expandedShellPartID}"]`)
+    const shellTrigger = shell.locator('[data-slot="collapsible-trigger"]')
+    const shellSubtitle = shell.locator('[data-slot="basic-tool-tool-subtitle"]')
+    await expect(shellSubtitle).toHaveCount(0)
+    await expect(shell.locator('[data-slot="bash-pre"]')).toContainText("$ bun typecheck")
+    await shellTrigger.click()
+    await expect(shellTrigger).toHaveAttribute("aria-expanded", "false")
+    await expect(shellSubtitle).toHaveText("bun typecheck")
+    await shellTrigger.click()
+    await expect(shellTrigger).toHaveAttribute("aria-expanded", "true")
+    await expect(shellSubtitle).toHaveCount(0)
   })
 })
 
@@ -339,7 +362,6 @@ async function configureSmokePage(page: Page, directory: string) {
           editToolPartsExpanded: true,
           shellToolPartsExpanded: true,
           showReasoningSummaries: true,
-          showSessionProgressBar: true,
         },
       }),
     )
@@ -706,7 +728,7 @@ async function navigateToSession(page: Page, directory: string, sessionId: strin
 }
 
 async function switchTitlebarSession(page: Page, sessionID: string, title: string) {
-  const href = `/${base64Encode(fixture.directory)}/session/${sessionID}`
+  const href = `/server/${base64Encode(fixture.serverKey)}/session/${sessionID}`
   const tab = page.locator(`[data-slot="titlebar-tabs"] a[href="${href}"]`).first()
   await expect(tab).toBeVisible()
   await tab.click()

packages/app/e2e/tsconfig.json

@@ -5,5 +5,12 @@
     "rootDir": "..",
     "types": ["node", "bun"]
   },
-  "include": ["./**/*.ts"]
+  "include": [
+    "./performance/timeline-stability/**/*.spec.ts",
+    "./performance/timeline-stability/fixture.test.ts",
+    "./performance/timeline-stability/fixture.ts",
+    "./performance/unit/visual-stability.test.ts",
+    "./regression/session-timeline-context-resize.spec.ts",
+    "./utils/**/*.ts"
+  ]
 }

packages/app/e2e/utils/mock-server.ts

@@ -1,16 +1,7 @@
 import type { Page, Route } from "@playwright/test"
 
-const emptyList = new Set([
-  "/skill",
-  "/command",
-  "/lsp",
-  "/formatter",
-  "/permission",
-  "/question",
-  "/vcs/status",
-  "/vcs/diff",
-])
-const emptyObject = new Set(["/global/config", "/config", "/provider/auth", "/mcp", "/session/status"])
+const emptyList = new Set(["/skill", "/command", "/lsp", "/formatter", "/vcs/status", "/vcs/diff"])
+const emptyObject = new Set(["/global/config", "/config", "/provider/auth", "/mcp"])
 
 export interface MockServerConfig {
   provider: unknown
@@ -18,13 +9,22 @@ export interface MockServerConfig {
   project: unknown
   sessions: ({ id: string } & Record<string, unknown>)[]
   pageMessages: (sessionId: string, limit: number, before?: string) => { items: unknown[]; cursor?: string }
+  vcsDiff?: unknown[]
   messageDelay?: number
   onMessages?: (input: { sessionID: string; before?: string; phase: "start" | "end" }) => void
   events?: () => unknown[]
   eventRetry?: number
+  todos?: (sessionID: string) => unknown[]
+  permissions?: unknown[] | (() => unknown[])
+  questions?: unknown[] | (() => unknown[])
+  fileList?: (path: string) => unknown | Promise<unknown>
+  fileContent?: (path: string) => unknown | Promise<unknown>
+  sessionStatus?: unknown
 }
 
 export async function mockOpenCodeServer(page: Page, config: MockServerConfig) {
+  const cursors = new Map<string, string>()
+  let nextCursor = 0
   const staticRoutes: Record<string, unknown> = {
     "/provider": config.provider,
     "/path": {
@@ -52,6 +52,16 @@ export async function mockOpenCodeServer(page: Page, config: MockServerConfig) {
     const path = url.pathname
     if (path === "/global/event" || path === "/event") return sse(route, config.events?.(), config.eventRetry)
     if (path === "/global/health") return json(route, { healthy: true })
+    if (path === "/permission")
+      return json(route, typeof config.permissions === "function" ? config.permissions() : (config.permissions ?? []))
+    if (path === "/question")
+      return json(route, typeof config.questions === "function" ? config.questions() : (config.questions ?? []))
+    if (path === "/session/status") return json(route, config.sessionStatus ?? {})
+    if (path === "/vcs/diff" && config.vcsDiff) return json(route, config.vcsDiff)
+    if (path === "/file" && config.fileList)
+      return json(route, await config.fileList(url.searchParams.get("path") ?? ""))
+    if (path === "/file/content" && config.fileContent)
+      return json(route, await config.fileContent(url.searchParams.get("path") ?? ""))
     if (emptyObject.has(path)) return json(route, {})
     if (emptyList.has(path)) return json(route, [])
     if (path in staticRoutes) return json(route, staticRoutes[path])
@@ -62,17 +72,24 @@ export async function mockOpenCodeServer(page: Page, config: MockServerConfig) {
       return json(route, session ?? {})
     }
 
-    if (/^\/session\/[^/]+\/(children|todo|diff)$/.test(path)) return json(route, [])
+    const todoMatch = path.match(/^\/session\/([^/]+)\/todo$/)
+    if (todoMatch) return json(route, config.todos?.(todoMatch[1]!) ?? [])
+    if (/^\/session\/[^/]+\/(children|diff)$/.test(path)) return json(route, [])
 
     const messagesMatch = path.match(/^\/session\/([^/]+)\/message$/)
     if (messagesMatch) {
-      const before = url.searchParams.get("before") ?? undefined
+      const token = url.searchParams.get("before") ?? undefined
+      const before = token ? cursors.get(token) : undefined
+      if (token && !before) return json(route, { error: "Invalid cursor" }, undefined, 400)
       config.onMessages?.({ sessionID: messagesMatch[1], before, phase: "start" })
       if (config.messageDelay) await new Promise((resolve) => setTimeout(resolve, config.messageDelay))
       const limit = Number(url.searchParams.get("limit") ?? 80)
       const pageData = config.pageMessages(messagesMatch[1], limit, before)
       config.onMessages?.({ sessionID: messagesMatch[1], before, phase: "end" })
-      return json(route, pageData.items, pageData.cursor ? { "x-next-cursor": pageData.cursor } : undefined)
+      if (!pageData.cursor) return json(route, pageData.items)
+      const cursor = `cursor_${++nextCursor}`
+      cursors.set(cursor, pageData.cursor)
+      return json(route, pageData.items, { "x-next-cursor": cursor })
     }
 
     if (url.port === targetPort && targetPort !== appPort) return json(route, {})
@@ -80,9 +97,9 @@ export async function mockOpenCodeServer(page: Page, config: MockServerConfig) {
   })
 }
 
-function json(route: Route, body: unknown, headers?: Record<string, string>) {
+function json(route: Route, body: unknown, headers?: Record<string, string>, status = 200) {
   return route.fulfill({
-    status: 200,
+    status,
     contentType: "application/json",
     headers: {
       "access-control-allow-origin": "*",

packages/app/e2e/utils/sse-transport.ts

@@ -0,0 +1,284 @@
+import type { Page } from "@playwright/test"
+
+export type SseConnectionRecord = {
+  id: number
+  url: string
+  path: "/global/event" | "/event"
+  headers: Record<string, string>
+  openedAt: number
+  endedAt?: number
+  endedBy?: "close" | "disconnect" | "error" | "abort"
+  error?: string
+}
+
+export type SseDeliveryAcknowledgement = {
+  deliveryID: number
+  connectionID: number
+  bytes: number
+  chunkCount: number
+  deliveredAt: number
+  eventID?: string
+}
+
+export type SseEventOptions = {
+  id?: string
+  event?: string
+  retry?: number
+  marker?: string
+}
+
+export type SseTransport<T> = {
+  server: string
+  waitForConnection(options?: { after?: number; timeout?: number }): Promise<SseConnectionRecord>
+  send(payload: T, options?: SseEventOptions): Promise<SseDeliveryAcknowledgement>
+  burst(payloads: readonly T[], options?: readonly SseEventOptions[]): Promise<SseDeliveryAcknowledgement[]>
+  split(payload: T, cuts: readonly number[], options?: SseEventOptions): Promise<SseDeliveryAcknowledgement>
+  heartbeat(options?: SseEventOptions): Promise<SseDeliveryAcknowledgement>
+  writeRaw(value: string | Uint8Array, cuts?: readonly number[], marker?: string): Promise<SseDeliveryAcknowledgement>
+  close(): Promise<void>
+  disconnect(message?: string): Promise<void>
+  error(message?: string): Promise<void>
+  connections(): Promise<SseConnectionRecord[]>
+  acknowledgements(): Promise<SseDeliveryAcknowledgement[]>
+}
+
+type BrowserCommand<T> =
+  | { type: "send"; deliveries: { payload: T; options?: SseEventOptions }[]; burst: boolean; cuts?: number[] }
+  | { type: "raw"; bytes: number[]; cuts?: number[]; marker?: string }
+  | { type: "end"; mode: "close" | "disconnect" | "error"; message?: string }
+  | { type: "connections" }
+  | { type: "acknowledgements" }
+
+type BrowserTransport = Window & {
+  __testSseTransport?: {
+    command: (command: BrowserCommand<unknown>) => unknown
+  }
+}
+
+export async function installSseTransport<T>(
+  page: Page,
+  options: { server: string; retry?: number },
+): Promise<SseTransport<T>> {
+  const server = new URL(options.server).origin
+  await page.addInitScript(
+    ({ server, retry }) => {
+      type Connection = SseConnectionRecord & { controller: ReadableStreamDefaultController<Uint8Array> }
+      type ProbeWindow = Window & {
+        __visualStabilityProbe?: { startedAt: number; markers: { at: number; label: string }[] }
+      }
+      const originalFetch = window.fetch.bind(window)
+      const connections: Connection[] = []
+      const acknowledgements: SseDeliveryAcknowledgement[] = []
+      const encoder = new TextEncoder()
+      let nextConnectionID = 0
+      let nextDeliveryID = 0
+
+      const current = () => connections.findLast((connection) => connection.endedAt === undefined)
+      const chunks = (bytes: Uint8Array, cuts?: readonly number[]) => {
+        const boundaries = [...new Set(cuts ?? [])]
+          .filter((cut) => Number.isInteger(cut) && cut > 0 && cut < bytes.byteLength)
+          .sort((a, b) => a - b)
+        return [0, ...boundaries].map((start, index) => bytes.slice(start, boundaries[index] ?? bytes.byteLength))
+      }
+      const marker = (label?: string) => {
+        if (!label) return
+        const probe = (window as ProbeWindow).__visualStabilityProbe
+        if (!probe) return
+        probe.markers.push({ at: performance.now() - probe.startedAt, label })
+      }
+      const frame = (payload: unknown, eventOptions: SseEventOptions = {}) =>
+        [
+          eventOptions.event === undefined ? "" : `event: ${eventOptions.event}\n`,
+          eventOptions.id === undefined ? "" : `id: ${eventOptions.id}\n`,
+          eventOptions.retry === undefined ? "" : `retry: ${eventOptions.retry}\n`,
+          `data: ${JSON.stringify(payload)}\n\n`,
+        ].join("")
+      const acknowledge = (
+        connection: Connection,
+        bytes: number,
+        chunkCount: number,
+        eventID?: string,
+      ): SseDeliveryAcknowledgement => {
+        const acknowledgement = {
+          deliveryID: ++nextDeliveryID,
+          connectionID: connection.id,
+          bytes,
+          chunkCount,
+          deliveredAt: performance.now(),
+          ...(eventID === undefined ? {} : { eventID }),
+        }
+        acknowledgements.push(acknowledgement)
+        return acknowledgement
+      }
+      const end = (mode: "close" | "disconnect" | "error", message?: string) => {
+        const connection = current()
+        if (!connection) throw new Error("SSE transport has no active connection")
+        connection.endedAt = performance.now()
+        connection.endedBy = mode
+        if (message) connection.error = message
+        if (mode === "close") {
+          connection.controller.close()
+          return
+        }
+        const error = new DOMException(
+          message ?? "SSE connection disconnected",
+          mode === "error" ? "Error" : "NetworkError",
+        )
+        connection.controller.error(error)
+      }
+
+      const command = (input: BrowserCommand<unknown>) => {
+        if (input.type === "connections")
+          return connections.map(({ controller: _controller, ...connection }) => connection)
+        if (input.type === "acknowledgements") return acknowledgements
+        if (input.type === "end") return end(input.mode, input.message)
+        const connection = current()
+        if (!connection) throw new Error("SSE transport has no active connection")
+        if (input.type === "raw") {
+          marker(input.marker)
+          const output = chunks(new Uint8Array(input.bytes), input.cuts)
+          output.forEach((chunk) => connection.controller.enqueue(chunk))
+          return acknowledge(connection, input.bytes.length, output.length)
+        }
+        const encoded = input.deliveries.map((delivery) => ({
+          delivery,
+          bytes: encoder.encode(frame(delivery.payload, delivery.options)),
+        }))
+        encoded.forEach((item) => marker(item.delivery.options?.marker))
+        if (input.burst) {
+          const bytes = encoder.encode(
+            encoded.map((item) => frame(item.delivery.payload, item.delivery.options)).join(""),
+          )
+          connection.controller.enqueue(bytes)
+          return encoded.map((item) => acknowledge(connection, item.bytes.byteLength, 1, item.delivery.options?.id))
+        }
+        const output = chunks(encoded[0]!.bytes, input.cuts)
+        output.forEach((chunk) => connection.controller.enqueue(chunk))
+        return acknowledge(connection, encoded[0]!.bytes.byteLength, output.length, encoded[0]!.delivery.options?.id)
+      }
+
+      ;(window as BrowserTransport).__testSseTransport = { command }
+      const fetch = (input: RequestInfo | URL, init?: RequestInit) => {
+        const request = new Request(input, init)
+        const url = new URL(request.url)
+        if (url.origin !== server || (url.pathname !== "/global/event" && url.pathname !== "/event"))
+          return originalFetch(input, init)
+
+        const id = ++nextConnectionID
+        const record = {
+          id,
+          url: url.href,
+          path: url.pathname,
+          headers: Object.fromEntries(request.headers.entries()),
+          openedAt: performance.now(),
+        } as Connection
+        const stream = new ReadableStream<Uint8Array>({
+          start(controller) {
+            record.controller = controller
+            connections.push(record)
+            if (retry !== undefined) controller.enqueue(encoder.encode(`retry: ${retry}\n\n`))
+            request.signal.addEventListener(
+              "abort",
+              () => {
+                if (record.endedAt !== undefined) return
+                record.endedAt = performance.now()
+                record.endedBy = "abort"
+                controller.error(request.signal.reason ?? new DOMException("The operation was aborted", "AbortError"))
+              },
+              { once: true },
+            )
+          },
+          cancel() {
+            if (record.endedAt !== undefined) return
+            record.endedAt = performance.now()
+            record.endedBy = "disconnect"
+          },
+        })
+        return Promise.resolve(
+          new Response(stream, {
+            status: 200,
+            headers: {
+              "cache-control": "no-cache",
+              "content-type": "text/event-stream",
+            },
+          }),
+        )
+      }
+      Object.defineProperty(window, "fetch", { configurable: true, writable: true, value: fetch })
+    },
+    { server, retry: options.retry },
+  )
+
+  const command = <Result>(input: BrowserCommand<T>) =>
+    page.evaluate((input) => {
+      const transport = (window as BrowserTransport).__testSseTransport
+      if (!transport) throw new Error("SSE transport was not installed before page load")
+      return transport.command(input as BrowserCommand<unknown>)
+    }, input) as Promise<Result>
+
+  return {
+    server,
+    async waitForConnection(input = {}) {
+      await page.waitForFunction(
+        (after) => {
+          const transport = (window as BrowserTransport).__testSseTransport
+          const connections = transport?.command({ type: "connections" }) as SseConnectionRecord[] | undefined
+          return connections?.some((connection) => connection.id > after)
+        },
+        input.after ?? 0,
+        { timeout: input.timeout },
+      )
+      return (await command<SseConnectionRecord[]>({ type: "connections" })).findLast(
+        (connection) => connection.id > (input.after ?? 0),
+      )!
+    },
+    send(payload, eventOptions) {
+      return command({ type: "send", deliveries: [{ payload, options: eventOptions }], burst: false })
+    },
+    burst(payloads, eventOptions = []) {
+      return command({
+        type: "send",
+        deliveries: payloads.map((payload, index) => ({ payload, options: eventOptions[index] })),
+        burst: true,
+      })
+    },
+    split(payload, cuts, eventOptions) {
+      return command({ type: "send", deliveries: [{ payload, options: eventOptions }], burst: false, cuts: [...cuts] })
+    },
+    heartbeat(eventOptions) {
+      return command({
+        type: "send",
+        deliveries: [
+          {
+            payload: { directory: "global", payload: { type: "server.heartbeat", properties: {} } } as T,
+            options: eventOptions,
+          },
+        ],
+        burst: false,
+      })
+    },
+    writeRaw(value, cuts, marker) {
+      return command({
+        type: "raw",
+        bytes: Array.from(typeof value === "string" ? new TextEncoder().encode(value) : value),
+        cuts: cuts ? [...cuts] : undefined,
+        marker,
+      })
+    },
+    close() {
+      return command({ type: "end", mode: "close" })
+    },
+    disconnect(message) {
+      return command({ type: "end", mode: "disconnect", message })
+    },
+    error(message) {
+      return command({ type: "end", mode: "error", message })
+    },
+    connections() {
+      return command({ type: "connections" })
+    },
+    acknowledgements() {
+      return command({ type: "acknowledgements" })
+    },
+  }
+}

packages/app/e2e/utils/visual-stability.ts

@@ -0,0 +1,54 @@
+import type { Page, TestInfo } from "@playwright/test"
+import { analyzeVisualObservations, analyzeVisualTraceByMarker } from "./visual-stability/analyzer"
+import { legacyVisualPlan, type LegacyVisualStabilityOptions } from "./visual-stability/invariant"
+import type { CapturedFrame, VisualStabilityTrace } from "./visual-stability/model"
+import { markVisualProbe, startVisualProbe, stopVisualProbe } from "./visual-stability/probe"
+import type { VisualRegionDefinition } from "./visual-stability/regions"
+import { reportVisualStability } from "./visual-stability/reporter"
+
+export * from "./visual-stability/index"
+
+const capturedFrames = Symbol("capturedFrames")
+
+export async function startVisualStabilityProbe(page: Page, regions: Record<string, VisualRegionDefinition>) {
+  await startVisualProbe(page, regions)
+}
+
+export async function stopVisualStabilityProbe(page: Page) {
+  const result = await stopVisualProbe(page)
+  const trace: VisualStabilityTrace = { markers: result.markers, samples: result.samples }
+  Object.defineProperty(trace, capturedFrames, { value: result.frames })
+  return trace
+}
+
+export async function markVisualStability(page: Page, label: string) {
+  await markVisualProbe(page, label)
+}
+
+export function analyzeVisualStability(trace: VisualStabilityTrace, options: LegacyVisualStabilityOptions = {}) {
+  return analyzeVisualObservations(trace.samples, legacyVisualPlan(options))
+}
+
+export function analyzeVisualStabilityByMarker(
+  trace: VisualStabilityTrace,
+  options: LegacyVisualStabilityOptions = {},
+) {
+  return analyzeVisualTraceByMarker(trace, legacyVisualPlan(options))
+}
+
+export async function expectVisualStability(
+  testInfo: TestInfo,
+  name: string,
+  trace: VisualStabilityTrace,
+  options: LegacyVisualStabilityOptions = {},
+) {
+  await reportVisualStability(
+    testInfo,
+    name,
+    {
+      ...trace,
+      frames: (trace as VisualStabilityTrace & { [capturedFrames]?: CapturedFrame[] })[capturedFrames] ?? [],
+    },
+    legacyVisualPlan(options),
+  )
+}

packages/app/e2e/utils/visual-stability/analyzer.ts

@@ -0,0 +1,209 @@
+import type { VisualInvariant, VisualPlan } from "./invariant"
+import type { VisualObservation, VisualStabilityTrace } from "./model"
+
+export function analyzeVisualObservations<RegionName extends string>(
+  observations: readonly VisualObservation<RegionName>[],
+  plan: VisualPlan<RegionName>,
+) {
+  const issues: string[] = []
+  const invariants = plan.invariants
+  const names = [...new Set(observations.flatMap((sample) => Object.keys(sample.regions) as RegionName[]))]
+  const required = regions(invariants, "required")
+  const continuousAny = invariants.filter(
+    (invariant): invariant is Extract<VisualInvariant<RegionName>, { type: "continuous-any" }> =>
+      invariant.type === "continuous-any",
+  )
+  const unique = new Set(regions(invariants, "unique"))
+  const stable = new Set(regions(invariants, "stable"))
+  const fixed = invariants.filter(
+    (invariant): invariant is Extract<VisualInvariant<RegionName>, { type: "fixed" }> => invariant.type === "fixed",
+  )
+  const opacity = invariants.filter(
+    (invariant): invariant is Extract<VisualInvariant<RegionName>, { type: "opacity" }> => invariant.type === "opacity",
+  )
+  const continuity = invariants.filter(
+    (invariant): invariant is Extract<VisualInvariant<RegionName>, { type: "continuity" }> =>
+      invariant.type === "continuity",
+  )
+  const motion = invariants.filter(
+    (invariant): invariant is Extract<VisualInvariant<RegionName>, { type: "motion" }> => invariant.type === "motion",
+  )
+  const labelStability = invariants.filter(
+    (invariant): invariant is Extract<VisualInvariant<RegionName>, { type: "label-stability" }> =>
+      invariant.type === "label-stability",
+  )
+
+  for (const name of new Set(required)) {
+    if (!observations.some((sample) => sample.regions[name]?.visible)) issues.push(`${name} never rendered`)
+  }
+  for (const invariant of continuousAny) {
+    if (!invariant.regions.some((name) => observations.some((sample) => sample.regions[name]?.visible)))
+      issues.push(`${invariant.regions.join(" | ")} never rendered`)
+  }
+
+  for (const name of names) {
+    const samples = observations.flatMap((observation) => {
+      const region = observation.regions[name]
+      if (!region) return []
+      const clipped =
+        observation.viewport && (region.bottom <= observation.viewport.top || region.top >= observation.viewport.bottom)
+      return [{ at: observation.at, ...region, visible: region.visible && !clipped }]
+    })
+    const visible = samples.filter((sample) => sample.visible)
+    if (visible.length === 0) continue
+    if (unique.has(name)) {
+      const duplicate = samples.find((sample) => sample.count > 1)
+      if (duplicate) issues.push(`${name} appeared ${duplicate.count} times at ${Math.round(duplicate.at)}ms`)
+    }
+    if (stable.has(name)) {
+      const identities = [...new Set(visible.map((sample) => sample.node).filter((node) => node > 0))]
+      if (identities.length > 1) issues.push(`${name} remounted ${identities.length - 1} times`)
+    }
+    for (const invariant of fixed.filter((invariant) => includes(invariant.regions, name))) {
+      const origin = visible[0]
+      const movement = origin ? Math.max(0, ...visible.map((sample) => Math.abs(sample.top - origin.top))) : 0
+      if (movement > (invariant.tolerance ?? 1))
+        issues.push(`${name} moved ${Math.round(movement * 10) / 10}px in the viewport`)
+    }
+    for (const invariant of opacity.filter((invariant) => includes(invariant.regions, name))) {
+      for (const sample of visible) {
+        if (sample.opacity < (invariant.floor ?? 0.65))
+          issues.push(`${name} opacity fell to ${sample.opacity} at ${Math.round(sample.at)}ms`)
+      }
+    }
+    if (continuity.some((invariant) => includes(invariant.regions, name))) {
+      const firstPresent = samples.findIndex((sample) => sample.present)
+      const lastPresent = samples.findLastIndex((sample) => sample.present)
+      if (samples.slice(firstPresent, lastPresent + 1).some((sample) => !sample.present))
+        issues.push(`${name} disappeared between present frames`)
+      const firstVisible = samples.findIndex((sample) => sample.visible)
+      const lastVisible = samples.findLastIndex((sample) => sample.visible)
+      if (
+        firstVisible >= 0 &&
+        samples.slice(firstVisible, lastVisible + 1).some((sample) => !sample.visible && sample.inViewport)
+      )
+        issues.push(`${name} blanked between visible frames`)
+    }
+    for (const invariant of motion.filter((invariant) => includes(invariant.regions, name))) {
+      for (const metric of ["top", "bottom", "width", "height"] as const) {
+        const directions = visible
+          .slice(1)
+          .map((sample, index) => sample[metric] - visible[index]![metric])
+          .filter((delta) => Math.abs(delta) > (invariant.tolerance ?? 1))
+          .map(Math.sign)
+        const reversals = directions.slice(1).filter((direction, index) => direction !== directions[index]).length
+        const allowed =
+          metric === "top" || metric === "bottom"
+            ? (invariant.maxPositionReversals ?? invariant.maxReversals ?? 1)
+            : (invariant.maxReversals ?? 1)
+        if (reversals > allowed) issues.push(`${name} ${metric} reversed ${reversals} times`)
+      }
+    }
+    if (labelStability.some((invariant) => includes(invariant.regions, name))) {
+      const labels = samples
+        .map((sample) => sample.label)
+        .filter((label) => label.length > 0)
+        .filter((label, index, all) => label !== all[index - 1])
+      if (labels.some((label, index) => labels.indexOf(label) !== index))
+        issues.push(`${name} label reverted: ${labels.join(" -> ")}`)
+    }
+  }
+
+  if (invariants.some((invariant) => invariant.type === "preserve-bottom-anchor")) {
+    const viewports = observations.flatMap((sample) => (sample.viewport ? [sample.viewport] : []))
+    if (viewports[0] && viewports[0].distanceFromBottom <= 4) {
+      const lost = viewports.find((viewport) => viewport.distanceFromBottom > 4)
+      if (lost) issues.push(`bottom anchor moved to ${lost.distanceFromBottom}px`)
+    }
+  }
+  if (invariants.some((invariant) => invariant.type === "acquire-bottom-anchor")) {
+    const final = observations.findLast((sample) => sample.viewport)?.viewport
+    if (!final || final.distanceFromBottom > 4)
+      issues.push(`did not acquire bottom anchor${final ? ` (${final.distanceFromBottom}px away)` : ""}`)
+  }
+
+  for (const invariant of continuousAny) {
+    const active = observations.map((sample) => invariant.regions.some((name) => sample.regions[name]?.visible))
+    const first = active.indexOf(true)
+    const last = active.lastIndexOf(true)
+    if (first >= 0 && active.slice(first, last + 1).some((value) => !value))
+      issues.push(`${invariant.regions.join(" | ")} blanked between visible frames`)
+  }
+
+  for (const invariant of invariants.filter(
+    (item): item is Extract<VisualInvariant<RegionName>, { type: "flow" }> => item.type === "flow",
+  )) {
+    for (const [before, after] of invariant.regions
+      .slice(1)
+      .map((after, index) => [invariant.regions[index]!, after])) {
+      let maximum: { overlap: number; at: number } | undefined
+      let inverted: { at: number } | undefined
+      for (const sample of observations) {
+        const first = sample.regions[before]
+        const second = sample.regions[after]
+        if (!first?.visible || !second?.visible) continue
+        if (
+          sample.viewport &&
+          (first.bottom <= sample.viewport.top ||
+            first.top >= sample.viewport.bottom ||
+            second.bottom <= sample.viewport.top ||
+            second.top >= sample.viewport.bottom)
+        )
+          continue
+        const overlap = first.bottom - second.top
+        if (first.top > second.top && !inverted) inverted = { at: sample.at }
+        if (overlap > (invariant.overlapTolerance ?? 0.5) && (!maximum || overlap > maximum.overlap))
+          maximum = { overlap, at: sample.at }
+      }
+      if (inverted) issues.push(`${before} rendered after ${after} at ${Math.round(inverted.at)}ms`)
+      if (maximum)
+        issues.push(
+          `${before} overlapped ${after} by ${Math.round(maximum.overlap * 10) / 10}px at ${Math.round(maximum.at)}ms`,
+        )
+    }
+  }
+  return [...new Set(issues)]
+}
+
+export function analyzeVisualTraceByMarker<RegionName extends string>(
+  trace: VisualStabilityTrace<RegionName>,
+  plan: VisualPlan<RegionName>,
+) {
+  if (trace.markers.length === 0) return analyzeVisualObservations(trace.samples, plan)
+  const required = [...new Set(plan.markerRequired ?? regions(plan.invariants, "required"))].flatMap((name) =>
+    trace.samples.some((sample) => sample.regions[name]?.visible) ? [] : [`${name} never rendered`],
+  )
+  const withoutRequired = plan.invariants.filter((invariant) => invariant.type !== "required")
+  const windows = trace.markers.flatMap((marker, index) => {
+    const end = trace.markers[index + 1]?.at ?? Infinity
+    const before = trace.samples.findLast((sample) => sample.at < marker.at)
+    const samples = [
+      ...(before ? [before] : []),
+      ...trace.samples.filter((sample) => sample.at >= marker.at && sample.at < end),
+    ]
+    if (samples.length < 2) return []
+    return analyzeVisualObservations(samples, { ...plan, perMarker: false, invariants: withoutRequired }).map(
+      (issue) => `${marker.label}: ${issue}`,
+    )
+  })
+  const aggregateMotion =
+    plan.aggregateMotion === false
+      ? []
+      : analyzeVisualObservations(trace.samples, {
+          invariants: plan.invariants.filter((invariant) => invariant.type === "motion"),
+        }).filter((issue) => / (?:top|bottom|width|height) reversed \d+ times$/.test(issue))
+  return [...new Set([...required, ...aggregateMotion, ...windows])]
+}
+
+function regions<RegionName extends string, Type extends VisualInvariant<RegionName>["type"]>(
+  invariants: readonly VisualInvariant<RegionName>[],
+  type: Type,
+) {
+  return invariants.flatMap((invariant) =>
+    invariant.type === type && "regions" in invariant && invariant.regions !== "all" ? [...invariant.regions] : [],
+  ) as RegionName[]
+}
+
+function includes<RegionName extends string>(regions: readonly RegionName[] | "all", name: RegionName) {
+  return regions === "all" || regions.includes(name)
+}

packages/app/e2e/utils/visual-stability/capture.ts

@@ -0,0 +1,51 @@
+import type { CDPSession, Page } from "@playwright/test"
+import type { CapturedFrame } from "./model"
+
+export type VisualCapture = {
+  session: CDPSession
+  frames: CapturedFrame[]
+  startedAtEpoch: number
+  running: boolean
+  capture: Promise<void>
+}
+
+export async function startVisualCapture(page: Page, startedAtEpoch: number) {
+  if (process.env.OPENCODE_STABILITY_CAPTURE !== "1") return
+  const session = await page.context().newCDPSession(page)
+  await session.send("Page.enable")
+  const recording: VisualCapture = {
+    session,
+    frames: [],
+    startedAtEpoch,
+    running: true,
+    capture: Promise.resolve(),
+  }
+  recording.capture = (async () => {
+    try {
+      while (recording.running && recording.frames.length < 900) {
+        const frame = await session.send("Page.captureScreenshot", {
+          format: "jpeg",
+          quality: 80,
+          captureBeyondViewport: false,
+          optimizeForSpeed: true,
+        })
+        recording.frames.push({ at: Date.now() - recording.startedAtEpoch, data: frame.data })
+        await new Promise((resolve) => setTimeout(resolve, 50))
+      }
+    } catch {
+      recording.running = false
+    }
+  })()
+  return recording
+}
+
+export async function stopVisualCapture(recording: VisualCapture | undefined) {
+  if (!recording) return []
+  recording.running = false
+  try {
+    await recording.capture
+  } finally {
+    await recording.session.detach().catch(() => undefined)
+  }
+  return recording.frames
+}

packages/app/e2e/utils/visual-stability/index.ts

@@ -0,0 +1,8 @@
+export * from "./analyzer"
+export * from "./capture"
+export * from "./invariant"
+export * from "./model"
+export * from "./probe"
+export * from "./regions"
+export * from "./reporter"
+export * from "./scenario"

packages/app/e2e/utils/visual-stability/invariant.ts

@@ -0,0 +1,112 @@
+import type { VisualRegionDefinition } from "./regions"
+
+type RegionSet<RegionName extends string> = readonly RegionName[] | "all"
+
+export type VisualInvariant<RegionName extends string = string> =
+  | { type: "required"; regions: readonly RegionName[] }
+  | { type: "continuous-any"; regions: readonly RegionName[] }
+  | { type: "unique"; regions: readonly RegionName[] }
+  | { type: "stable"; regions: readonly RegionName[] }
+  | { type: "fixed"; regions: readonly RegionName[]; tolerance?: number }
+  | { type: "opacity"; regions: RegionSet<RegionName>; floor?: number }
+  | {
+      type: "motion"
+      regions: RegionSet<RegionName>
+      tolerance?: number
+      maxReversals?: number
+      maxPositionReversals?: number
+    }
+  | { type: "continuity"; regions: RegionSet<RegionName> }
+  | { type: "label-stability"; regions: RegionSet<RegionName> }
+  | { type: "flow"; regions: readonly RegionName[]; overlapTolerance?: number }
+  | { type: "preserve-bottom-anchor" }
+  | { type: "acquire-bottom-anchor" }
+
+export type VisualPlan<RegionName extends string = string> = {
+  regionNames?: readonly RegionName[]
+  invariants: readonly VisualInvariant<RegionName>[]
+  markerRequired?: readonly RegionName[]
+  perMarker?: boolean
+  aggregateMotion?: boolean
+}
+
+export type LegacyVisualStabilityOptions<RegionName extends string = string> = {
+  flow?: RegionName[]
+  motionTolerance?: number
+  opacityFloor?: number
+  overlapTolerance?: number
+  maxReversals?: number
+  maxPositionReversals?: number
+  stable?: RegionName[]
+  fixed?: RegionName[]
+  motion?: RegionName[]
+  unique?: RegionName[]
+  preserveBottomAnchor?: boolean
+  acquireBottomAnchor?: boolean
+  perMarker?: boolean
+  continuousAny?: RegionName[][]
+  required?: RegionName[]
+  aggregateMotion?: boolean
+  inferRequired?: boolean
+}
+
+export function visualPlan<const Regions extends Record<string, VisualRegionDefinition>>(
+  regions: Regions,
+  invariants: readonly VisualInvariant<Extract<keyof Regions, string>>[],
+  options: Omit<VisualPlan<Extract<keyof Regions, string>>, "regionNames" | "invariants"> = {},
+): VisualPlan<Extract<keyof Regions, string>> {
+  return { ...options, regionNames: Object.keys(regions) as Extract<keyof Regions, string>[], invariants }
+}
+
+export function legacyVisualPlan<RegionName extends string>(
+  options: LegacyVisualStabilityOptions<RegionName> = {},
+): VisualPlan<RegionName> {
+  const inferred =
+    options.inferRequired === false
+      ? []
+      : [
+          ...(options.stable ?? []),
+          ...(options.fixed ?? []),
+          ...(options.unique ?? []),
+          ...(options.motion ?? []),
+          ...(options.flow ?? []),
+        ]
+  return {
+    perMarker: options.perMarker,
+    aggregateMotion: options.aggregateMotion,
+    markerRequired: [
+      ...(options.required ?? []),
+      ...(options.stable ?? []),
+      ...(options.fixed ?? []),
+      ...(options.unique ?? []),
+      ...(options.motion ?? []),
+      ...(options.flow ?? []),
+    ],
+    invariants: [
+      { type: "required", regions: [...(options.required ?? []), ...inferred] },
+      ...(options.continuousAny ?? []).map(
+        (regions): VisualInvariant<RegionName> => ({ type: "continuous-any", regions }),
+      ),
+      ...(options.unique ? [{ type: "unique" as const, regions: options.unique }] : []),
+      ...(options.stable ? [{ type: "stable" as const, regions: options.stable }] : []),
+      ...(options.fixed
+        ? [{ type: "fixed" as const, regions: options.fixed, tolerance: options.motionTolerance }]
+        : []),
+      { type: "opacity", regions: "all", floor: options.opacityFloor },
+      { type: "continuity", regions: "all" },
+      {
+        type: "motion",
+        regions: options.motion ?? "all",
+        tolerance: options.motionTolerance,
+        maxReversals: options.maxReversals,
+        maxPositionReversals: options.maxPositionReversals,
+      },
+      { type: "label-stability", regions: "all" },
+      ...(options.preserveBottomAnchor ? [{ type: "preserve-bottom-anchor" as const }] : []),
+      ...(options.acquireBottomAnchor ? [{ type: "acquire-bottom-anchor" as const }] : []),
+      ...(options.flow
+        ? [{ type: "flow" as const, regions: options.flow, overlapTolerance: options.overlapTolerance }]
+        : []),
+    ],
+  }
+}

packages/app/e2e/utils/visual-stability/model.ts

@@ -0,0 +1,47 @@
+export type VisualRegionSample = {
+  present: boolean
+  visible: boolean
+  inViewport: boolean
+  cssHidden?: boolean
+  top: number
+  bottom: number
+  layoutTop?: number
+  layoutBottom?: number
+  width: number
+  height: number
+  opacity: number
+  count: number
+  node: number
+  label: string
+  text: string
+}
+
+export type VisualViewportSample = {
+  top: number
+  bottom: number
+  scrollTop: number
+  scrollHeight: number
+  clientHeight: number
+  distanceFromBottom: number
+}
+
+export type VisualObservation<RegionName extends string = string> = {
+  at: number
+  regions: string extends RegionName
+    ? Record<string, VisualRegionSample>
+    : Partial<Record<RegionName, VisualRegionSample>>
+  viewport?: VisualViewportSample
+}
+
+export type VisualMarker = { at: number; label: string }
+
+export type VisualStabilityTrace<RegionName extends string = string> = {
+  markers: VisualMarker[]
+  samples: VisualObservation<RegionName>[]
+}
+
+export type CapturedFrame = { at: number; data: string }
+
+export type VisualProbeResult<RegionName extends string = string> = VisualStabilityTrace<RegionName> & {
+  frames: CapturedFrame[]
+}

packages/app/e2e/utils/visual-stability/probe.ts

@@ -0,0 +1,226 @@
+import type { Page } from "@playwright/test"
+import { startVisualCapture, stopVisualCapture, type VisualCapture } from "./capture"
+import type { VisualMarker, VisualObservation, VisualProbeResult } from "./model"
+import type { VisualRegionDefinition } from "./regions"
+
+type ProbeWindow<RegionName extends string = string> = Window & {
+  __visualStabilityProbe?: {
+    startedAt: number
+    markers: VisualMarker[]
+    samples: VisualObservation<RegionName>[]
+    stop: () => void
+  }
+}
+
+const captures = new WeakMap<Page, VisualCapture>()
+
+export async function startVisualProbe<Regions extends Record<string, VisualRegionDefinition>>(
+  page: Page,
+  regions: Regions,
+) {
+  await stopCapture(page)
+  await page.evaluate(() => {
+    ;(window as ProbeWindow).__visualStabilityProbe?.stop()
+  })
+  const startedAtEpoch = await page.evaluate((regions) => {
+    const samples: VisualObservation[] = []
+    const markers: VisualMarker[] = []
+    const startedAt = performance.now()
+    const nodes = new WeakMap<Node, number>()
+    const lastBounds = new Map<string, { top: number; bottom: number }>()
+    let nextNode = 1
+    let running = true
+    const round = (value: number) => Math.round(value * 10) / 10
+    const opacity = (element: Element) => Number(getComputedStyle(element).opacity)
+    const sample = () => {
+      if (!running) return
+      setTimeout(() => {
+        if (!running) return
+        const viewport = [...document.querySelectorAll<HTMLElement>(".scroll-view__viewport")].find((element) =>
+          element.querySelector("[data-timeline-row]"),
+        )
+        const viewportRect = viewport?.getBoundingClientRect()
+        samples.push({
+          at: performance.now() - startedAt,
+          viewport: viewport
+            ? {
+                top: round(viewportRect!.top),
+                bottom: round(viewportRect!.bottom),
+                scrollTop: round(viewport.scrollTop),
+                scrollHeight: round(viewport.scrollHeight),
+                clientHeight: round(viewport.clientHeight),
+                distanceFromBottom: round(viewport.scrollHeight - viewport.clientHeight - viewport.scrollTop),
+              }
+            : undefined,
+          regions: Object.fromEntries(
+            Object.entries(regions).map(([name, config]) => {
+              const found = document.querySelector<HTMLElement>(config.selector)
+              const count = document.querySelectorAll(config.selector).length
+              const element = config.closest ? found?.closest<HTMLElement>(config.closest) : found
+              if (!element)
+                return [
+                  name,
+                  {
+                    present: false,
+                    visible: false,
+                    inViewport: false,
+                    top: 0,
+                    bottom: 0,
+                    width: 0,
+                    height: 0,
+                    opacity: 0,
+                    count,
+                    node: 0,
+                    label: "",
+                    text: "",
+                  },
+                ]
+              const rect = element.getBoundingClientRect()
+              const style = getComputedStyle(element)
+              if (rect.height > 0) lastBounds.set(name, { top: rect.top, bottom: rect.bottom })
+              const known = rect.height > 0 ? rect : lastBounds.get(name)
+              const painted = (() => {
+                const result = { top: rect.top, bottom: rect.bottom, left: rect.left, right: rect.right }
+                let parent = element.parentElement
+                while (parent) {
+                  const parentStyle = getComputedStyle(parent)
+                  if (["hidden", "clip", "scroll", "auto"].includes(parentStyle.overflowY)) {
+                    const parentRect = parent.getBoundingClientRect()
+                    result.top = Math.max(result.top, parentRect.top)
+                    result.bottom = Math.min(result.bottom, parentRect.bottom)
+                  }
+                  if (["hidden", "clip", "scroll", "auto"].includes(parentStyle.overflowX)) {
+                    const parentRect = parent.getBoundingClientRect()
+                    result.left = Math.max(result.left, parentRect.left)
+                    result.right = Math.min(result.right, parentRect.right)
+                  }
+                  if (parent === viewport) break
+                  parent = parent.parentElement
+                }
+                if (viewportRect) {
+                  result.top = Math.max(result.top, viewportRect.top)
+                  result.bottom = Math.min(result.bottom, viewportRect.bottom)
+                  result.left = Math.max(result.left, viewportRect.left)
+                  result.right = Math.min(result.right, viewportRect.right)
+                }
+                return result
+              })()
+              const contentOpacity = config.opacitySelectors?.length
+                ? Math.max(
+                    0,
+                    ...config.opacitySelectors.flatMap((selector) =>
+                      [...element.querySelectorAll(selector)].map((node) => {
+                        let value = 1
+                        let current: Element | null = node
+                        while (current) {
+                          value *= opacity(current)
+                          if (current === element) break
+                          current = current.parentElement
+                        }
+                        return value
+                      }),
+                    ),
+                  )
+                : opacity(element)
+              let visibleOpacity = contentOpacity
+              let ancestor = element.parentElement
+              let ancestorHidden = false
+              while (ancestor) {
+                const ancestorStyle = getComputedStyle(ancestor)
+                visibleOpacity *= Number(ancestorStyle.opacity)
+                if (ancestorStyle.display === "none" || ancestorStyle.visibility === "hidden") ancestorHidden = true
+                if (ancestor === viewport) break
+                ancestor = ancestor.parentElement
+              }
+              const cssHidden =
+                ancestorHidden || style.display === "none" || style.visibility === "hidden" || visibleOpacity === 0
+              return [
+                name,
+                {
+                  present: true,
+                  visible:
+                    style.display !== "none" &&
+                    style.visibility !== "hidden" &&
+                    visibleOpacity > 0 &&
+                    painted.right > painted.left &&
+                    painted.bottom > painted.top,
+                  inViewport:
+                    !viewportRect || (!!known && known.bottom > viewportRect.top && known.top < viewportRect.bottom),
+                  cssHidden,
+                  top: round(painted.top),
+                  bottom: round(painted.bottom),
+                  layoutTop: round(rect.top),
+                  layoutBottom: round(rect.bottom),
+                  width: round(painted.right - painted.left),
+                  height: round(painted.bottom - painted.top),
+                  opacity: round(visibleOpacity),
+                  count,
+                  node: (() => {
+                    const current = nodes.get(element)
+                    if (current) return current
+                    nodes.set(element, nextNode)
+                    return nextNode++
+                  })(),
+                  label: element.getAttribute("aria-label") ?? "",
+                  text: (element.textContent ?? "").trim().replace(/\s+/g, " ").slice(0, 500),
+                },
+              ]
+            }),
+          ),
+        })
+        requestAnimationFrame(sample)
+      }, 0)
+    }
+    ;(window as ProbeWindow).__visualStabilityProbe = {
+      startedAt,
+      markers,
+      samples,
+      stop: () => {
+        running = false
+      },
+    }
+    requestAnimationFrame(sample)
+    return new Promise<number>((resolve) => {
+      const ready = () => {
+        if (samples.length > 0) return resolve(performance.timeOrigin + startedAt)
+        requestAnimationFrame(ready)
+      }
+      ready()
+    })
+  }, regions)
+  const capture = await startVisualCapture(page, startedAtEpoch)
+  if (capture) captures.set(page, capture)
+}
+
+export async function stopVisualProbe<RegionName extends string = string>(
+  page: Page,
+): Promise<VisualProbeResult<RegionName>> {
+  return page
+    .evaluate(() => {
+      const probe = (window as ProbeWindow).__visualStabilityProbe
+      if (!probe) throw new Error("Visual stability probe is not running")
+      probe.stop()
+      return { markers: probe.markers, samples: probe.samples }
+    })
+    .then(
+      async (trace) => ({ ...trace, frames: await stopCapture(page) }) as unknown as VisualProbeResult<RegionName>,
+      async (error: unknown) => {
+        await stopCapture(page)
+        throw error
+      },
+    )
+}
+
+export async function markVisualProbe(page: Page, label: string) {
+  await page.evaluate((label) => {
+    const probe = (window as ProbeWindow).__visualStabilityProbe
+    if (!probe) return
+    probe.markers.push({ at: performance.now() - probe.startedAt, label })
+  }, label)
+}
+
+async function stopCapture(page: Page) {
+  const capture = captures.get(page)
+  if (capture) captures.delete(page)
+  return stopVisualCapture(capture)
+}

packages/app/e2e/utils/visual-stability/regions.ts

@@ -0,0 +1,18 @@
+export type VisualRegionDefinition = {
+  selector: string
+  closest?: string
+  opacitySelectors?: readonly string[]
+}
+
+export function defineVisualRegions<const Regions extends Record<string, VisualRegionDefinition>>(regions: Regions) {
+  return regions
+}
+
+export function mapVisualRegions<const Regions extends Record<string, VisualRegionDefinition>, Result>(
+  regions: Regions,
+  map: (region: Regions[keyof Regions], name: keyof Regions) => Result,
+) {
+  return Object.fromEntries(
+    Object.entries(regions).map(([name, region]) => [name, map(region as Regions[keyof Regions], name)]),
+  ) as { [Name in keyof Regions]: Result }
+}

packages/app/e2e/utils/visual-stability/reporter.ts

@@ -0,0 +1,63 @@
+import { expect, type TestInfo } from "@playwright/test"
+import { writeFile } from "node:fs/promises"
+import { analyzeVisualObservations, analyzeVisualTraceByMarker } from "./analyzer"
+import type { VisualPlan } from "./invariant"
+import type { VisualProbeResult } from "./model"
+
+export async function reportVisualStability<RegionName extends string>(
+  testInfo: TestInfo,
+  name: string,
+  result: VisualProbeResult<RegionName>,
+  plan: VisualPlan<RegionName>,
+) {
+  const trace = { markers: result.markers, samples: result.samples }
+  const issues = plan.perMarker
+    ? analyzeVisualTraceByMarker(trace, plan)
+    : analyzeVisualObservations(result.samples, plan)
+  const tracePath = testInfo.outputPath(`${name}-visual-trace.json`)
+  const issuesPath = testInfo.outputPath(`${name}-visual-issues.json`)
+  await writeFile(tracePath, JSON.stringify(trace, null, 2))
+  await writeFile(
+    issuesPath,
+    JSON.stringify({ issues, markers: result.markers, capturedFrameCount: result.frames.length }, null, 2),
+  )
+  await testInfo.attach(`${name}-visual-trace`, { path: tracePath, contentType: "application/json" })
+  await testInfo.attach(`${name}-visual-issues`, { path: issuesPath, contentType: "application/json" })
+  if (issues.length) await attachViolationFrames(testInfo, name, result, issues)
+  expect(issues, `${name}: ${issues.join("\n")}`).toEqual([])
+}
+
+async function attachViolationFrames<RegionName extends string>(
+  testInfo: TestInfo,
+  name: string,
+  result: VisualProbeResult<RegionName>,
+  issues: string[],
+) {
+  if (result.frames.length === 0) return
+  const targets = [
+    ...new Set(
+      issues.flatMap((issue) => {
+        const match = issue.match(/ at (\d+)ms/)
+        if (match) return [Number(match[1])]
+        const marker = result.markers.find((item) => issue.startsWith(`${item.label}:`))
+        return marker ? [marker.at] : []
+      }),
+    ),
+  ].slice(0, 6)
+  for (const [violation, target] of targets.entries()) {
+    const nearest = result.frames.reduce(
+      (best, frame, index) => (Math.abs(frame.at - target) < Math.abs(result.frames[best]!.at - target) ? index : best),
+      0,
+    )
+    for (const [label, index] of [
+      ["before", Math.max(0, nearest - 1)],
+      ["violation", nearest],
+      ["after", Math.min(result.frames.length - 1, nearest + 1)],
+    ] as const) {
+      await testInfo.attach(`${name}-${violation + 1}-${label}-${Math.round(result.frames[index]!.at)}ms`, {
+        body: Buffer.from(result.frames[index]!.data, "base64"),
+        contentType: "image/jpeg",
+      })
+    }
+  }
+}

packages/app/e2e/utils/visual-stability/scenario.ts

@@ -0,0 +1,20 @@
+import type { Page, TestInfo } from "@playwright/test"
+import type { VisualPlan } from "./invariant"
+import { startVisualProbe, stopVisualProbe } from "./probe"
+import type { VisualRegionDefinition } from "./regions"
+import { reportVisualStability } from "./reporter"
+
+export async function runVisualStabilityScenario<const Regions extends Record<string, VisualRegionDefinition>>(input: {
+  page: Page
+  testInfo: TestInfo
+  name: string
+  regions: Regions
+  plan: VisualPlan<Extract<keyof Regions, string>>
+  run: () => Promise<void>
+}) {
+  await startVisualProbe(input.page, input.regions)
+  await input.run()
+  const result = await stopVisualProbe<Extract<keyof Regions, string>>(input.page)
+  await reportVisualStability(input.testInfo, input.name, result, input.plan)
+  return result
+}

packages/app/index.html

@@ -1,22 +1,28 @@
 <!doctype html>
-<html lang="en" style="background-color: var(--background-base)">
+<html lang="en" style="background-color: var(--v2-background-bg-deep, #fafafa)">
   <head>
     <meta charset="utf-8" />
-    <meta name="viewport" content="width=device-width, initial-scale=1, interactive-widget=resizes-content" />
+    <meta
+      name="viewport"
+      content="width=device-width, initial-scale=1, interactive-widget=resizes-content, viewport-fit=cover"
+    />
     <title>OpenCode</title>
     <link rel="icon" type="image/png" href="/favicon-96x96-v3.png" sizes="96x96" />
     <link rel="icon" type="image/svg+xml" href="/favicon-v3.svg" />
     <link rel="shortcut icon" href="/favicon-v3.ico" />
     <link rel="apple-touch-icon" sizes="180x180" href="/apple-touch-icon-v3.png" />
     <link rel="manifest" href="/site.webmanifest" />
-    <meta name="theme-color" content="#F8F7F7" />
+    <meta name="theme-color" content="#fafafa" />
+    <meta name="mobile-web-app-capable" content="yes" />
+    <meta name="apple-mobile-web-app-capable" content="yes" />
+    <meta name="apple-mobile-web-app-status-bar-style" content="black-translucent" />
     <meta property="og:image" content="/social-share.png" />
     <meta property="twitter:image" content="/social-share.png" />
     <script id="oc-theme-preload-script" src="/oc-theme-preload.js"></script>
   </head>
-  <body class="antialiased overscroll-none text-12-regular overflow-hidden">
+  <body class="antialiased overscroll-none text-12-regular overflow-hidden bg-v2-background-bg-deep">
     <noscript>You need to enable JavaScript to run this app.</noscript>
-    <div id="root" class="flex flex-col h-dvh p-px"></div>
+    <div id="root" class="flex flex-col h-dvh bg-v2-background-bg-deep p-px"></div>
     <script src="/src/entry.tsx" type="module"></script>
   </body>
 </html>

packages/app/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@opencode-ai/app",
-  "version": "1.17.9",
+  "version": "1.17.13",
   "description": "",
   "type": "module",
   "exports": {
@@ -13,18 +13,20 @@
   },
   "scripts": {
     "typecheck": "tsgo -b",
+    "typecheck:e2e": "tsgo -p e2e/tsconfig.json",
     "start": "vite",
     "dev": "vite",
     "build": "vite build",
     "serve": "vite preview",
-    "test": "bun run test:unit && bun run test:virtualizer",
+    "test": "bun run test:unit && bun run test:browser",
     "test:unit": "bun test --only-failures --preload ./happydom.ts ./src",
-    "test:virtualizer": "bun test --conditions=browser --preload ./happydom.ts ./test-browser/solid-virtual.test.ts",
+    "test:browser": "bun test --conditions=browser --preload ./happydom.ts ./test-browser",
     "test:unit:watch": "bun test --watch --preload ./happydom.ts ./src",
     "test:e2e": "playwright test",
     "test:e2e:local": "playwright test",
     "test:e2e:ui": "playwright test --ui",
     "test:e2e:report": "playwright show-report e2e/playwright-report",
+    "test:stability": "bun test ./e2e/performance/unit/visual-stability.test.ts && playwright test --config e2e/performance/timeline-stability/playwright.config.ts",
     "test:bench": "bun test ./e2e/performance/unit && playwright test --config e2e/performance/playwright.config.ts"
   },
   "license": "MIT",
@@ -38,15 +40,22 @@
     "@types/luxon": "catalog:",
     "@types/node": "catalog:",
     "@typescript/native-preview": "catalog:",
+    "tw-animate-css": "1.4.0",
     "typescript": "catalog:",
     "vite": "catalog:",
     "vite-plugin-icons-spritesheet": "3.0.1",
     "vite-plugin-solid": "catalog:"
   },
   "dependencies": {
+    "@dnd-kit/abstract": "0.5.0",
+    "@dnd-kit/dom": "0.5.0",
+    "@dnd-kit/helpers": "0.5.0",
+    "@dnd-kit/solid": "0.5.0",
     "@kobalte/core": "catalog:",
     "@opencode-ai/core": "workspace:*",
+    "@opencode-ai/schema": "workspace:*",
     "@opencode-ai/sdk": "workspace:*",
+    "@opencode-ai/session-ui": "workspace:*",
     "@opencode-ai/ui": "workspace:*",
     "@pierre/trees": "1.0.0-beta.4",
     "@sentry/solid": "catalog:",
@@ -71,7 +80,7 @@
     "diff": "catalog:",
     "effect": "catalog:",
     "fuzzysort": "catalog:",
-    "ghostty-web": "github:anomalyco/ghostty-web#main",
+    "ghostty-web": "github:anomalyco/ghostty-web#513463a6f1190253057e8a3f0dac8f6ee8393553",
     "luxon": "catalog:",
     "marked": "catalog:",
     "marked-shiki": "catalog:",

packages/app/public/oc-theme-preload.js

@@ -15,10 +15,11 @@
 
   document.documentElement.dataset.theme = themeId
   document.documentElement.dataset.colorScheme = mode
+  document.documentElement.style.backgroundColor = isDark ? "#080808" : "#fafafa"
 
   // Update theme-color meta tag to match app color scheme
   var metas = document.querySelectorAll("meta[name='theme-color']")
-  if (metas.length > 0) metas[0].setAttribute("content", isDark ? "#131010" : "#F8F7F7")
+  if (metas.length > 0) metas[0].setAttribute("content", isDark ? "#080808" : "#fafafa")
 
   if (themeId === "oc-2") return
 

packages/app/src/app.tsx

@@ -4,7 +4,7 @@ import { I18nProvider } from "@opencode-ai/ui/context"
 import { DialogProvider } from "@opencode-ai/ui/context/dialog"
 import { FileComponentProvider } from "@opencode-ai/ui/context/file"
 import { MarkedProvider } from "@opencode-ai/ui/context/marked"
-import { File } from "@opencode-ai/ui/file"
+import { File } from "@opencode-ai/session-ui/file"
 import { Font } from "@opencode-ai/ui/font"
 import { Splash } from "@opencode-ai/ui/logo"
 import { ThemeProvider } from "@opencode-ai/ui/theme/context"
@@ -16,6 +16,7 @@ import {
   type Component,
   createEffect,
   createMemo,
+  createRenderEffect,
   createResource,
   createSignal,
   ErrorBoundary,
@@ -27,97 +28,109 @@ import {
   Show,
 } from "solid-js"
 import { Dynamic } from "solid-js/web"
-import { CommandProvider } from "@/context/command"
+import { CommandProvider, useCommand, type CommandOption } from "@/context/command"
 import { CommentsProvider } from "@/context/comments"
 import { FileProvider } from "@/context/file"
 import { ServerSDKProvider } from "@/context/server-sdk"
 import { ServerSyncProvider } from "@/context/server-sync"
-import { GlobalProvider } from "@/context/global"
+import { GlobalProvider, useGlobal } from "@/context/global"
 import { HighlightsProvider } from "@/context/highlights"
 import { LanguageProvider, type Locale, useLanguage } from "@/context/language"
 import { LayoutProvider } from "@/context/layout"
 import { ModelsProvider } from "@/context/models"
 import { NotificationProvider } from "@/context/notification"
 import { PermissionProvider } from "@/context/permission"
+import { usePlatform } from "@/context/platform"
 import { PromptProvider } from "@/context/prompt"
 import { ServerConnection, ServerProvider, serverName, useServer } from "@/context/server"
 import { SettingsProvider, useSettings } from "@/context/settings"
-import { TerminalProvider } from "@/context/terminal"
 import { TabsProvider, useTabs, type DraftTab } from "@/context/tabs"
 import { SDKProvider, useSDK } from "@/context/sdk"
 import { WslServersProvider } from "@/wsl/context"
 import DirectoryLayout, { DirectoryDataProvider } from "@/pages/directory-layout"
-import Layout from "@/pages/layout"
+import LegacyLayout from "@/pages/layout"
+import NewLayout from "@/pages/layout-new"
 import { ErrorPage } from "./pages/error"
 import { useCheckServerHealth } from "./utils/server-health"
+import { legacySessionServer, requireServerKey, sessionHref } from "./utils/session-route"
+
+import { SessionPage, TargetSessionRouteContent } from "@/pages/session"
+import { NewHome, LegacyHome } from "@/pages/home"
 
-const HomeRoute = lazy(() => import("@/pages/home"))
-const Session = lazy(() => import("@/pages/session"))
 const NewSession = lazy(() => import("@/pages/new-session"))
 
-const SessionRoute = Object.assign(
-  () => {
-    const settings = useSettings()
-    const params = useParams()
-    const [search] = useSearchParams<{ draftId?: string; prompt?: string }>()
-    const sdk = useSDK()
-    const server = useServer()
-    const tabs = useTabs()
-
-    // When the new layout is enabled, the legacy new-session route (/:dir/session with no id)
-    // is replaced by a draft at /new-session?draftId=…
-    createEffect(() => {
-      if (!settings.general.newLayoutDesigns()) return
-      if (params.id || search.draftId) return
-      if (!tabs.ready() || !sdk().directory) return
-      tabs.newDraft({ server: server.key, directory: sdk().directory }, search.prompt)
-    })
+const SessionRoute = () => {
+  const settings = useSettings()
+  const params = useParams()
+  const [search] = useSearchParams<{ draftId?: string; prompt?: string }>()
+  const sdk = useSDK()
+  const server = useServer()
+  const tabs = useTabs()
 
+  if (params.id && settings.general.newLayoutDesigns()) {
+    const sessionID = params.id
     return (
-      <SessionProviders>
-        <Session />
-      </SessionProviders>
+      <Show when={tabs.ready()}>
+        {(_) => {
+          const persisted = tabs.store.filter((item) => item.type === "session")
+          return <Navigate href={sessionHref(legacySessionServer(persisted, sessionID, server.key), sessionID)} />
+        }}
+      </Show>
     )
-  },
-  { preload: Session.preload },
-)
+  }
+
+  // When the new layout is enabled, the legacy new-session route (/:dir/session with no id)
+  // is replaced by a draft at /new-session?draftId=…
+  createEffect(() => {
+    if (!settings.general.newLayoutDesigns()) return
+    if (params.id || search.draftId) return
+    if (!tabs.ready() || !sdk().directory) return
+    tabs.newDraft({ server: server.key, directory: sdk().directory }, search.prompt)
+  })
+
+  return <SessionPage />
+}
+
+const TargetSessionRoute = () => {
+  const params = useParams<{ serverKey: string; id: string }>()
+  const global = useGlobal()
+  const conn = createMemo(() => {
+    const key = requireServerKey(params.serverKey)
+    return global.servers.list().find((item) => ServerConnection.key(item) === key)
+  })
+
+  return (
+    // Owns the server-identity remount. Session changes must NOT remount this
+    // subtree (SessionRouteErrorBoundary resets and createSessionLineage
+    // re-resolves reactively instead); both rely on this key for server changes.
+    <Show when={requireServerKey(params.serverKey)} keyed>
+      <ServerSDKProvider server={conn}>
+        <ServerSyncProvider server={conn}>
+          <TargetSessionRouteContent />
+        </ServerSyncProvider>
+      </ServerSDKProvider>
+    </Show>
+  )
+}
 
 // Wraps the non-draft routes. They are gated on (and keyed to) the globally selected
 // server via ServerKey, then provide the server-scoped shell (Permission/Layout/
 // Notification/Models + the visual Layout) for that server.
-function SelectedServerLayout(props: ParentProps) {
+function SelectedServerProviders(props: ParentProps) {
   return (
     <ServerKey>
       <ServerSDKProvider>
-        <ServerSyncProvider>
-          <ServerScopedShell>{props.children}</ServerScopedShell>
-        </ServerSyncProvider>
+        <ServerSyncProvider>{props.children}</ServerSyncProvider>
       </ServerSDKProvider>
     </ServerKey>
   )
 }
 
-// Wraps /new-session. It resolves the draft's target server and provides the
-// server-scoped shell for that server — without ServerKey, so the page never depends
-// on the globally "selected" server.
-function DraftServerLayout(props: ParentProps) {
-  const server = useServer()
-  const tabs = useTabs()
-  const [search] = useSearchParams<{ draftId?: string }>()
-  const conn = createMemo(() => {
-    const id = search.draftId
-    if (!id) return undefined
-    const draft = tabs.store.find((tab): tab is DraftTab => tab.type === "draft" && tab.draftID === id)
-    if (!draft) return undefined
-    return server.list.find((c) => ServerConnection.key(c) === draft.server)
-  })
-
+function LegacyServerLayout(props: ParentProps) {
   return (
-    <ServerSDKProvider server={conn}>
-      <ServerSyncProvider server={conn}>
-        <ServerScopedShell>{props.children}</ServerScopedShell>
-      </ServerSyncProvider>
-    </ServerSDKProvider>
+    <SelectedServerProviders>
+      <LegacyServerScopedShell>{props.children}</LegacyServerScopedShell>
+    </SelectedServerProviders>
   )
 }
 
@@ -126,36 +139,38 @@ function DraftRoute() {
   const tabs = useTabs()
   return (
     <Show when={tabs.ready()}>
-      <Show when={search.draftId} keyed fallback={<Navigate href="/" />}>
-        {(draftID) => <ResolvedDraftRoute draftID={draftID} />}
+      <Show
+        when={tabs.store.find((tab): tab is DraftTab => tab.type === "draft" && tab.draftID === search.draftId)}
+        keyed
+        fallback={<Navigate href="/" />}
+      >
+        {(draft) => <ResolvedDraftRoute draft={draft} />}
       </Show>
     </Show>
   )
 }
 
-function ResolvedDraftRoute(props: { draftID: string }) {
-  const tabs = useTabs()
-  const draft = createMemo(() =>
-    tabs.store.find((tab): tab is DraftTab => tab.type === "draft" && tab.draftID === props.draftID),
-  )
-
-  // Key on the directory so retargeting the draft's project re-instantiates the
-  // directory-scoped providers while keeping the same draft id. The draft's target
-  // server is provided by DraftServerLayout, so changing only the server updates the
-  // SDK/sync hooks without remounting the composer.
-  const directory = () => draft()?.directory
+function ResolvedDraftRoute(props: { draft: DraftTab }) {
+  const global = useGlobal()
+  const conn = createMemo(() => global.servers.list().find((item) => ServerConnection.key(item) === props.draft.server))
+  const directory = () => props.draft.directory
+  const serverKey = () => props.draft.server
 
   return (
-    <Show when={directory()} keyed>
-      {(dir) => (
-        <SDKProvider directory={dir}>
-          <DirectoryDataProvider directory={dir} draftID={props.draftID}>
-            <DraftProviders>
-              <NewSession />
-            </DraftProviders>
-          </DirectoryDataProvider>
-        </SDKProvider>
-      )}
+    <Show when={`${props.draft.server}\0${props.draft.directory}`} keyed>
+      <ServerSDKProvider server={conn}>
+        <ServerSyncProvider server={conn}>
+          <DraftServerScopedProviders directory={directory}>
+            <SDKProvider directory={directory}>
+              <DirectoryDataProvider directory={directory} server={serverKey}>
+                <DraftProviders>
+                  <NewSession />
+                </DraftProviders>
+              </DirectoryDataProvider>
+            </SDKProvider>
+          </DraftServerScopedProviders>
+        </ServerSyncProvider>
+      </ServerSDKProvider>
     </Show>
   )
 }
@@ -193,10 +208,11 @@ function QueryProvider(props: ParentProps) {
 function BodyDesignClass() {
   const settings = useSettings()
 
-  createEffect(() => {
+  createRenderEffect(() => {
     if (typeof document === "undefined") return
 
     const enabled = settings.general.newLayoutDesigns()
+    document.body.toggleAttribute("data-new-layout", enabled)
     document.body.classList.toggle("text-12-regular", !enabled)
     document.body.classList.toggle("font-(family-name:--font-family-text)", enabled)
     document.body.classList.toggle("text-[13px]", enabled)
@@ -210,41 +226,78 @@ function BodyDesignClass() {
 // shell (router root) so they stay mounted regardless of the active server/route.
 function SharedProviders(props: ParentProps) {
   return (
-    <SettingsProvider>
+    <>
       <BodyDesignClass />
       <CommandProvider>
+        <DesktopCommands />
         <HighlightsProvider>{props.children}</HighlightsProvider>
       </CommandProvider>
-    </SettingsProvider>
+    </>
   )
 }
 
-// Server-scoped providers plus the visual Layout (tabs/sidebar). These live inside
-// each per-route server layout so they resolve to that route's server (selected vs
-// draft). The Layout remounts when crossing between those groups.
-function ServerScopedShell(props: ParentProps) {
+function DesktopCommands() {
+  const command = useCommand()
+  const language = useLanguage()
+  const platform = usePlatform()
+
+  command.register("desktop", () => {
+    const commands: CommandOption[] = []
+    if (platform.platform === "desktop" && platform.exportDebugLogs) {
+      commands.push({
+        id: "logs.export",
+        title: "Export logs",
+        category: language.t("command.category.settings"),
+        onSelect: () => {
+          void platform.exportDebugLogs?.()
+        },
+      })
+    }
+    return commands
+  })
+
+  return null
+}
+
+// Server-scoped providers shared by the legacy shell and the top-level new shell.
+type ServerScopedShellProps = ParentProps<{
+  directory?: () => string | undefined
+  sessionID?: () => string | undefined
+}>
+
+function ServerScopedProviders(props: ServerScopedShellProps) {
   return (
-    <PermissionProvider>
+    <PermissionProvider directory={props.directory}>
       <LayoutProvider>
-        <NotificationProvider>
-          <ModelsProvider>
-            <Layout>{props.children}</Layout>
-          </ModelsProvider>
-        </NotificationProvider>
+        <ModelsProvider directory={props.directory}>{props.children}</ModelsProvider>
       </LayoutProvider>
     </PermissionProvider>
   )
 }
 
-function SessionProviders(props: ParentProps) {
+function LegacyServerScopedShell(props: ServerScopedShellProps) {
   return (
-    <TerminalProvider>
-      <FileProvider>
-        <PromptProvider>
-          <CommentsProvider>{props.children}</CommentsProvider>
-        </PromptProvider>
-      </FileProvider>
-    </TerminalProvider>
+    <ServerScopedProviders directory={props.directory} sessionID={props.sessionID}>
+      <LegacyLayout>{props.children}</LegacyLayout>
+    </ServerScopedProviders>
+  )
+}
+
+function NewAppLayout(props: ParentProps) {
+  return (
+    <SelectedServerProviders>
+      <ServerScopedProviders>
+        <NewLayout>{props.children}</NewLayout>
+      </ServerScopedProviders>
+    </SelectedServerProviders>
+  )
+}
+
+function DraftServerScopedProviders(props: ParentProps<{ directory?: () => string | undefined }>) {
+  return (
+    <PermissionProvider directory={props.directory}>
+      <ModelsProvider directory={props.directory}>{props.children}</ModelsProvider>
+    </PermissionProvider>
   )
 }
 
@@ -418,11 +471,9 @@ export function AppInterface(props: {
   router?: Component<BaseRouterProps>
   disableHealthCheck?: boolean
 }) {
-  // The shared shell holds only server-agnostic providers (QueryClient + Settings/
-  // Command/Highlights) and stays mounted across every route. The server-scoped
-  // providers and the visual Layout live in the per-route layouts below, so they
-  // resolve to that route's server (selected for most routes, the draft's server for
-  // /new-session). appChildren is server-agnostic, so it renders here once.
+  // The visual new layout lives in the router root so it remains mounted across
+  // route changes. Draft and session routes override only their server-bound data
+  // providers beneath it.
   const ServerShell = (shellProps: ParentProps) => (
     <QueryProvider>
       <SharedProviders>
@@ -439,28 +490,72 @@ export function AppInterface(props: {
       servers={props.servers}
     >
       <GlobalProvider>
-        <ConnectionGate disableHealthCheck={props.disableHealthCheck}>
-          <Dynamic
-            component={props.router ?? Router}
-            root={(routerProps) => (
-              <TabsProvider>
-                <ServerShell>{routerProps.children}</ServerShell>
-              </TabsProvider>
-            )}
-          >
-            <Route component={SelectedServerLayout}>
-              <Route path="/" component={HomeRoute} />
-              <Route path="/:dir" component={DirectoryLayout}>
-                <Route path="/" component={() => <Navigate href="session" />} />
-                <Route path="/session/:id?" component={SessionRoute} />
-              </Route>
-            </Route>
-            <Route component={DraftServerLayout}>
-              <Route path="/new-session" component={DraftRoute} />
-            </Route>
-          </Dynamic>
-        </ConnectionGate>
+        <SettingsProvider>
+          <ConnectionGate disableHealthCheck={props.disableHealthCheck}>
+            <Show when={useSettings().general.newLayoutDesigns().toString()} keyed>
+              <Dynamic
+                component={props.router ?? Router}
+                root={(routerProps) => (
+                  <TabsProvider>
+                    <NotificationProvider>
+                      <ServerShell>
+                        <Show when={useSettings().general.newLayoutDesigns()} fallback={routerProps.children}>
+                          <NewAppLayout>{routerProps.children}</NewAppLayout>
+                        </Show>
+                      </ServerShell>
+                    </NotificationProvider>
+                  </TabsProvider>
+                )}
+              >
+                <Routes />
+              </Dynamic>
+            </Show>
+          </ConnectionGate>
+        </SettingsProvider>
       </GlobalProvider>
     </ServerProvider>
   )
 }
+
+function Routes() {
+  const settings = useSettings()
+
+  return (
+    <>
+      <Route component={LegacyServerLayout}>
+        <Show when={!settings.general.newLayoutDesigns()}>{<Route path="/" component={LegacyHome} />}</Show>
+        <Route path="/:dir" component={DirectoryLayout}>
+          <Route path="/" component={() => <Navigate href="session" />} />
+          <Route path="/session/:id?" component={SessionRoute} />
+        </Route>
+      </Route>
+      <Show when={settings.general.newLayoutDesigns()}>
+        <Route path="/" component={NewHome} />
+        <Route path="/:dir/session/:id" component={LegacyTargetSessionRoute} />
+      </Show>
+      <Route path="/new-session" component={DraftRoute} />
+      <Route path="/server/:serverKey/session/:id" component={TargetSessionRoute} />
+    </>
+  )
+}
+
+function LegacyTargetSessionRoute() {
+  const server = useServer()
+  const tabs = useTabs()
+  const params = useParams<{ id: string }>()
+
+  return (
+    <Show when={tabs.ready()}>
+      <Navigate
+        href={sessionHref(
+          legacySessionServer(
+            tabs.store.filter((item) => item.type === "session"),
+            params.id,
+            server.key,
+          ),
+          params.id,
+        )}
+      />
+    </Show>
+  )
+}