Switch the OpenAPI document used by the SDK build (and `bun dev generate`)
from the legacy Hono backend to `OpenApi.fromApi(PublicApi)`.
The Effect HttpApi backend already covers every Hono route — the bridge
test in `httpapi-bridge.test.ts` audits this — and `PublicApi` already
applies the legacy-shape transforms (instance query params, optional-null
stripping, SSE schemas, component renames). The spec-emitting path was
the last piece still rooted in Hono.
The Hono path is preserved as `Server.openapiHono()` and `bun dev generate
--hono` so reviewers can diff the two outputs while the Hono backend
lingers; both go away with the Hono backend itself.
Verified the new default matches the previous `--httpapi` output
byte-for-byte and the SDK build round-trips cleanly.
Kit Langton