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

src/ZB.MOM.WW.MxGateway.Worker/MxAccess/AlarmRecordTransitionMapper.cs

@@ -49,6 +49,17 @@ public static class AlarmRecordTransitionMapper
     ///         <item><description><c>previous=*Rtn</c> + <c>current=*Alm</c> → Raise (re-trigger after clear).</description></item>
     ///         <item><description>Anything else → Unspecified (no proto kind to emit).</description></item>
     ///     </list>
+    ///     <para>
+    ///         <see cref="AlarmTransitionKind.Retrigger"/> is never returned. It is
+    ///         reserved in the contract, but neither alarm source gives the worker
+    ///         a native re-alarm signal: the alarmmgr XML carries only the four
+    ///         <c>*_ALM</c>/<c>*_RTN</c> states, so a return-to-alarm is
+    ///         indistinguishable from a fresh raise and is reported as Raise, and
+    ///         the subtag source observes no re-alarm counter. Deliberately not
+    ///         synthesized (the gateway forwards only transitions the source
+    ///         reports — see docs/AlarmClientDiscovery.md, "Retrigger
+    ///         transitions").
+    ///     </para>
     /// </summary>
     /// <param name="previous">The previous alarm state kind.</param>
     /// <param name="current">The current alarm state kind.</param>