worker(alarms): synthetic GUID + degraded/source_provider on emitted transitions

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

@@ -86,6 +86,12 @@ public sealed class MxAccessAlarmEventSink : IMxAccessEventSink
     /// <param name="operatorComment">The operator's comment, if any.</param>
     /// <param name="category">The alarm category.</param>
     /// <param name="description">The alarm description.</param>
+    /// <param name="degraded">
+    ///     <see langword="true"/> when the transition was synthesized by the
+    ///     subtag-provider fallback rather than the native alarmmgr path.
+    ///     Defaults to <see langword="false"/> so existing alarmmgr callers
+    ///     compile unchanged and stay on the parity (alarmmgr) path.
+    /// </param>
     internal void EnqueueTransition(
         string alarmFullReference,
         string sourceObjectReference,
@@ -97,10 +103,16 @@ public sealed class MxAccessAlarmEventSink : IMxAccessEventSink
         string operatorUser,
         string operatorComment,
         string category,
-        string description)
+        string description,
+        bool degraded = false)
     {
         try
         {
+            // Degraded transitions come from the subtag fallback; the native
+            // alarmmgr (wnwrap) path stays degraded=false / ALARMMGR for parity.
+            AlarmProviderMode sourceProvider = degraded
+                ? AlarmProviderMode.Subtag
+                : AlarmProviderMode.Alarmmgr;
             MxEvent mxEvent = eventMapper.CreateOnAlarmTransition(
                 sessionId,
                 alarmFullReference,
@@ -114,7 +126,9 @@ public sealed class MxAccessAlarmEventSink : IMxAccessEventSink
                 operatorComment,
                 category,
                 description,
-                statuses: null);
+                statuses: null,
+                degraded: degraded,
+                sourceProvider: sourceProvider);
             eventQueue.Enqueue(mxEvent);
         }
         catch (Exception exception)