- Wait for the chat SSE heartbeat goroutine to exit before the handler
returns, so it cannot write a recycled connection
- Extend /tasks/run write deadline to 75m so long sync runs are not cut
by the global 120s WriteTimeout before the response is written
- Reuse an existing task run on the SSE path when the idempotency key
already belongs to the same user/session/project
- Log stale fencing on event ack so unbounded replay is observable
Co-authored-by: Cursor <cursoragent@cursor.com>