Residuals of #760:
1. An ack routed to a disabled / not-yet-spawned driver, or to a stubbed child
(driver does not run on this node, or its factory rejected the config), was
dropped and left the condition Acknowledged. DriverHostActor now reverts it
through the same NativeAlarmProjector.TryRevertAcknowledge path as a refused
ack.
2. A native ack arriving while the host is Stale was dropped before the projector
recorded it, so it could never be reverted. Stale now marks the whole
NativeAlarmAckPreflightView unavailable (SetHostUnavailable), so the node
manager refuses every native ack synchronously; BecomeSteady clears it.
3. (keyed sessions without a Galaxy identity) is not addressed.
Tests: DriverHostActorNativeAlarmTests' client-ack test and the FOCAS respawn
theory now start the host's own driver (AckingAlarmDriver; a factory building a
real FocasDriver per spawn over per-instance fake CNCs, with a real config-change
respawn) - both fail against the fix in their old shape. New: ack to a disabled
driver reverts, ack to a stubbed driver reverts, a Stale host refuses through the
pre-check view - all three fail with the fix mutated out. Runtime.Tests 943/0/3.
Docs: AlarmTracking.md, .claude/rules/alarms.md.
Claude-Session: https://claude.ai/code/session_01GT67AEHd2Acv1YPwGfXEoV
Joseph Doherty