drop) instead of flipping to completed. Adds heartbeat (25s ping/10s pong), reconnect with infinite jittered backoff, outbound queue gated
on resume_ack, gap_detected fallback for long offlines, on-disk persistence of terminal events for post-restart recovery, and a
reconnecting connection state decoupled from session.status. 1089 backend tests covering 500 randomized disconnect scenarios + concurrent
broadcast races. Backend/WS handler does not cancel agent task on disconnect