`[2026-06-30]` **Worldtree v1.0.0b1→b2 consumer adaptation: eager turn-launch statuses (`v0.18.3` `b2e4901`, `v0.18.4` `e4317f6`).** Worldtree #331 decoupled turn execution from the SSE connection → turn-launch failures now arrive EAGERLY as a status before any stream: 409 `agent_not_available` (pre-b1 a 200 + in-stream error event), 503 retryable. Mapped both in `stream_turn` to typed `SseConnectFailed` subclasses keyed on STATUS, parsing the `{detail:{error_code,message}}` envelope — POST-003 preserved (no synthetic event yielded), existing handlers still catch (the design fork vs yield-an-Error-event was decided by POST-003). **DEFERRED follow-ups** (tracked here; bundle with the v1 coverage-audit): (1) live-prove the 409/503 end-to-end on personal-b2 (now unblocked — personal on b2, my key works there); (2) full `conversation-api-spec.md` markdown re-vendor to the b2 era (ratatoskr vendors the markdown, not the OpenAPI JSON).
