Nineteenth (final) PR of the alarms-over-gateway epic. Pins the
public RPC handler contract added in PR A.3:
- AcknowledgeAlarm rejects empty session_id and empty
alarm_full_reference with InvalidArgument.
- AcknowledgeAlarm with valid input returns OK and a
worker-pending diagnostic so clients see a successful round-trip
even before A.2's worker dispatch lands.
- QueryActiveAlarms rejects empty session_id with InvalidArgument.
- QueryActiveAlarms with valid input streams zero snapshots until
PR A.2 wires the worker-side QueryActiveAlarmsCommand
(filter-prefix passthrough verified at the proto layer).
- OpenSession advertises both new RPC capability strings
(unary-acknowledge-alarm, server-stream-active-alarms) so client
capability negotiation lights up against the contract surface.
Closes Track A's gateway-side surface. The remaining worker
ConditionRefresh walk + integration parity-rig validation lands
during dev-rig hardware validation alongside PR A.2's COM-side
alarm subscription pin.
Tests: 279 passed (was 273; 6 new). Per-handler integration tests
land alongside the dev-rig validation when the worker walks the
real MxAccess active-alarm collection.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Joseph Doherty