Refuse archiving a running session and turns in an archived one
A session can no longer be archived while its turn runs, and an archived session takes no new turns, steers or approvals.
Two gaps are fixed together:
- Archiving a session with a running turn used to succeed while the turn kept running on the agent. It now answers
conflict, as discarding a running session already did. - An archived session used to accept new turns, and an approval the agent was waiting on could still be answered. Submits, steers and approval answers now answer
conflictuntil the session is restored.
Replays are answered first, so a retried archive or message still gets its original reply.
Evidence
No screenshot: The app already refuses to archive a working session; this closes the same gap in the executor, for races and other clients.