fix(opencode): order legacy message loop by time (#40990)

Co-authored-by: Dax <mail@thdxr.com>

packages/opencode/src/session/message-v2.ts

@@ -577,29 +577,32 @@ export const filterCompactedEffect = Effect.fnUntraced(function* (sessionID: Ses
 
 // filterCompacted reorders messages for model consumption
 // ([compaction-user, summary, ...retained tail..., continue-user]), so array
-// position is not chronological. Derive each binding by max id (MessageID
-// is monotonic via MessageID.ascending) so a pre-compaction overflowing tail
-// assistant doesn't get mistaken for the most recent turn. tasks are
-// compaction/subtask parts attached to user messages newer than the latest
-// finished assistant — i.e. unprocessed work.
+// position is not chronological. IDs are only a deterministic tie-breaker
+// because imported messages do not necessarily have monotonic IDs.
 export function latest(msgs: WithParts[]) {
   let user: User | undefined
   let assistant: Assistant | undefined
   let finished: Assistant | undefined
   for (const msg of msgs) {
     const info = msg.info
-    if (info.role === "user" && (!user || info.id > user.id)) user = info
-    if (info.role === "assistant" && (!assistant || info.id > assistant.id)) assistant = info
-    if (info.role === "assistant" && info.finish && (!finished || info.id > finished.id)) finished = info
+    if (info.role === "user" && isAfter(info, user)) user = info
+    if (info.role === "assistant" && isAfter(info, assistant)) assistant = info
+    if (info.role === "assistant" && info.finish && isAfter(info, finished)) finished = info
   }
   const tasks = msgs.flatMap((m) =>
-    finished && m.info.id <= finished.id
+    finished && !isAfter(m.info, finished)
       ? []
       : m.parts.filter((p): p is CompactionPart | SubtaskPart => p.type === "compaction" || p.type === "subtask"),
   )
   return { user, assistant, finished, tasks }
 }
 
+function isAfter(info: Info, other?: Info) {
+  if (!other) return true
+  if (info.time.created !== other.time.created) return info.time.created > other.time.created
+  return info.id > other.id
+}
+
 export function fromError(
   e: unknown,
   ctx: { providerID: ProviderV2.ID; aborted?: boolean },

packages/opencode/src/session/prompt.ts

@@ -1112,7 +1112,7 @@ const layer = Layer.effect(
             lastAssistant?.finish &&
             !["tool-calls"].includes(lastAssistant.finish) &&
             !hasToolCalls &&
-            lastUser.id < lastAssistant.id
+            lastAssistant.parentID === lastUser.id
           ) {
             const orphan = lastAssistantMsg?.parts.find(
               (part): part is SessionV1.ToolPart => part.type === "tool" && isOrphanedInterruptedTool(part),