fix(worker): review 2026-10-21 stream E — cache eviction, phased ReadBulk, poll/STA fault handling

- RemoveItem/Unregister evict value + write-completion caches (leak under churn)
- ReadBulk snapshot path: add/advise all, one shared deadline, then tear down
- alarm poll faults only after 3 consecutive failures; transient ones logged
- AlarmCommandHandler disposes primary when standby build throws
- StaRuntime pumps between queued work items
- WRK-02: post-start STA loop death surfaces as StaHung WorkerFault
- WRK-09: AppDomain unhandled-exception hook, exit code 7
- RETRIGGER documented as reserved, never synthesized
- TST-05: live facts for Ping/GetSessionState/GetWorkerInfo/DrainEvents/ShutdownWorker

docs/AlarmClientDiscovery.md

@@ -1051,6 +1051,18 @@ Every transition and snapshot record carries `degraded = true` and
 `source_provider = ALARM_PROVIDER_MODE_SUBTAG`. Clients that require full
 fidelity must wait for failback to the alarm manager.
 
+### Retrigger transitions
+
+`ALARM_TRANSITION_KIND_RETRIGGER` is reserved in the contract and the worker
+never emits it, in either provider mode. The alarmmgr XML reports only the
+four states `UNACK_ALM`, `ACK_ALM`, `UNACK_RTN`, and `ACK_RTN`, so a condition
+that returns to alarm after clearing (`*_RTN` → `*_ALM`) looks the same as a
+new raise, and `AlarmRecordTransitionMapper.MapTransition` reports it as
+`ALARM_TRANSITION_KIND_RAISE`. The subtag source has no re-alarm counter to
+observe either. The worker does not infer a retrigger from timing or
+from a raise that follows a clear, because the gateway forwards only
+transitions its source reports.
+
 ### Provider mode reflection
 
 When `FailoverAlarmConsumer` switches between providers, it raises