docs(historian): alerts-fed historization (scripted, Primary-gated, exactly-once) + config-gated Sqlite→Wonderware sink

docs/AlarmTracking.md

@@ -178,9 +178,12 @@ AB CIP ALMD) route to AVEVA Historian via the Wonderware sidecar:
   silent data loss without log scraping.
 - `HistorianAdapterActor`
   (`src/Server/ZB.MOM.WW.OtOpcUa.Runtime/Historian/HistorianAdapterActor.cs`)
-  bridges Akka cluster messages from `ScriptedAlarmActor` into the
-  sink's `EnqueueAsync`; fire-and-forget so the actor loop is never
-  blocked on historian reachability.
+  subscribes to the cluster `alerts` DPS topic, translates each
+  `AlarmTransitionEvent` → `AlarmHistorianEvent`, and calls
+  `EnqueueAsync` fire-and-forget. Primary-gated — only the Primary node
+  historizes, giving exactly-once writes across a redundant pair. See
+  [AlarmHistorian.md §Configuration](AlarmHistorian.md#configuration)
+  for the `AlarmHistorian` appsettings section that enables the real sink.
 
 Galaxy-native alarms with `$Alarm*` extensions reach AVEVA Historian
 directly via System Platform's `HistorizeToAveva` toggle on the