Stream Session

SSE tail of the session's event stream, by seq cursor.

Live view and replay are the same endpoint: pass ?cursor= (or the SSE Last-Event-ID header on reconnect) to resume. Emits:

• event: message frames (id: = the row's seq; data = run message)
• event: turn frames whenever a turn's status changes (the composer's end-of-turn signal)
• : ping comments to keep intermediaries from buffering.

Deliberately DB-tail polling (~400ms) decoupled from the intake POST: refresh-safe, and how a scheduled turn is watched live. The overlap re-read is time-based and generous; the client dedupes by seq.