1.12.0
Maintenance mode
Maintenance mode brings the Server to a controlled stop so the infrastructure underneath it can be changed — switching the message broker, migrating the database, restarting for an upgrade — without losing work in flight.
Opening a window queues new work rather than refusing it, and lets dispatched jobs finish. A window then moves through four phases: Draining and Ready for maintenance wait, Reconciling and Resuming act. Each names what is holding it back — the specific jobs, missions and queues — so a stalled drain is diagnosable rather than a guess. Scheduled work is re-derived from the database on the way out, so heartbeats, drift checks and timeouts survive a broker that was replaced underneath them.
Closing is refused where it would strand parked work. Two failsafes cover the rest: cancel all open jobs, and cancel missions whose agent is no longer reachable.
The Admin Center gains a Maintenance page with the phase timeline and live monitors for jobs, missions and queue depths, plus a banner on every organization page while a window is open.