Phase B native alarms never fired end-to-end: GalaxyDriver suppresses OnAlarmEvent until
an alarm subscription exists (_alarmSubscriptions.Count > 0), but the runtime only attached
the OnAlarmEvent handler and never called SubscribeAlarmsAsync — so the central feed stayed
gated and no transition reached the Part 9 condition / /alerts. Unit tests passed because
they inject through the IAlarmSource seam directly; the deferred live /run surfaced it.
DriverHostActor computes per-driver alarm refs (alarm-bearing tags' FullNames) and hands them
via SetDesiredSubscriptions; DriverInstanceActor calls SubscribeAlarmsAsync for IAlarmSource
drivers on Connected entry and whenever alarm refs are pushed while Connected (the deploy path),
idempotent via a cached handle reset on detach so reconnect re-subscribes.
Add AllDeadLetters probe to Native_alarm_during_reconnect_is_dropped_not_forwarded so the
test genuinely guards the Reconnecting state's Receive<NativeAlarmRaised> drop handler —
removing that handler would now cause a dead-letter and fail the assertion (false-negative
gap closed). Reword the ScriptedAlarms.md severity-mapping note: "snaps on the first
transition" → "every transition maps … overriding the authored seed from the first
transition onward", clarifying that MapSeverity runs on every event, not just the first.
Joseph Doherty