feat(debugview): DV-1 native-binding linkage on AlarmStateChanged contract chain

Add two additive init-only fields to AlarmStateChanged so the Debug View can
nest live native conditions under their configured source-binding node:
  - NativeSourceCanonicalName (binding canonical name, e.g. "Motor1.MotorAlarms")
  - IsConfiguredPlaceholder (quiet-binding placeholder flag; default false)

Flow on BOTH cross-process paths:
  - Live: proto AlarmStateUpdate fields 22/23 -> StreamRelayActor packs ->
    SiteStreamGrpcClient unpacks (regenerated SiteStreamGrpc/Sitestream.cs).
  - Snapshot (Newtonsoft): record defaults carry through; no special handling.

NativeAlarmActor.Emit now stamps NativeSourceCanonicalName = _source.CanonicalName.
Additive-only: no existing positional constructor or wire frame changed.

Tests: StreamRelayActorTests round-trips both fields pack->unpack;
NativeAlarmActorTests asserts the emitted event carries the binding canonical name.

tests/ZB.MOM.WW.ScadaBridge.Communication.Tests/Grpc/StreamRelayActorTests.cs

@@ -113,6 +113,52 @@ public class StreamRelayActorTests : TestKit
         Assert.Equal("90", alarm.LimitValue);
     }
 
+    [Fact]
+    public void RelaysAlarmStateChanged_NativeBindingLinkage_SurvivesFullRoundTrip()
+    {
+        // DV-1: the native source-binding canonical name and the configured-placeholder
+        // flag must pack into AlarmStateUpdate (StreamRelayActor) and unpack back out
+        // (SiteStreamGrpcClient.ConvertToDomainEvent) — the full cross-process round trip.
+        var channel = Channel.CreateUnbounded<SiteStreamEvent>();
+        var actor = Sys.ActorOf(Props.Create(() =>
+            new StreamRelayActor("corr-native-binding", channel.Writer)));
+
+        var timestamp = new DateTimeOffset(2026, 3, 21, 11, 0, 0, TimeSpan.Zero);
+        var domainEvent = new AlarmStateChanged(
+            "Site1.Motor01", "Motor1.MotorAlarms.Hi", AlarmState.Active, 900, timestamp)
+        {
+            Kind = AlarmKind.NativeOpcUa,
+            SourceReference = "Motor1.MotorAlarms.Hi",
+            NativeSourceCanonicalName = "Motor1.MotorAlarms",
+            IsConfiguredPlaceholder = true,
+            Condition = new AlarmConditionState(
+                Active: true, Acknowledged: false, Confirmed: null,
+                Shelve: AlarmShelveState.Unshelved, Suppressed: false, Severity: 900)
+        };
+
+        actor.Tell(domainEvent);
+
+        var success = channel.Reader.TryRead(out var protoEvent);
+        if (!success)
+        {
+            Thread.Sleep(500);
+            success = channel.Reader.TryRead(out protoEvent);
+        }
+
+        Assert.True(success, "Expected a proto event on the channel");
+        Assert.NotNull(protoEvent);
+
+        // Packed onto the wire frame by StreamRelayActor.
+        Assert.Equal("Motor1.MotorAlarms", protoEvent.AlarmChanged.NativeSourceCanonicalName);
+        Assert.True(protoEvent.AlarmChanged.IsConfiguredPlaceholder);
+
+        // Unpacked back into the domain record by SiteStreamGrpcClient.
+        var roundTripped = Assert.IsType<AlarmStateChanged>(
+            SiteStreamGrpcClient.ConvertToDomainEvent(protoEvent));
+        Assert.Equal("Motor1.MotorAlarms", roundTripped.NativeSourceCanonicalName);
+        Assert.True(roundTripped.IsConfiguredPlaceholder);
+    }
+
     [Fact]
     public void SetsCorrelationId_OnAllEvents()
     {

tests/ZB.MOM.WW.ScadaBridge.SiteRuntime.Tests/Actors/NativeAlarmActorTests.cs

@@ -79,6 +79,27 @@ public class NativeAlarmActorTests : TestKit, IDisposable
         Assert.Equal(800, emitted.Condition.Severity);
     }
 
+    [Fact]
+    public void Raise_StampsNativeSourceCanonicalName_FromConfiguredBinding()
+    {
+        // DV-1: every emitted condition carries the canonical name of the source
+        // BINDING it belongs to, so the DebugView can nest live native conditions
+        // under their configured binding node. It must equal the binding's
+        // CanonicalName used to construct the actor (Source().CanonicalName).
+        var instance = CreateTestProbe();
+        var dcl = CreateTestProbe();
+        var actor = Spawn(instance.Ref, dcl.Ref);
+        dcl.ExpectMsg<SubscribeAlarmsRequest>();
+
+        actor.Tell(new NativeAlarmTransitionUpdate("Opc", Transition(
+            "T01.Hi", AlarmTransitionKind.Raise,
+            new AlarmConditionState(true, false, null, AlarmShelveState.Unshelved, false, 800))));
+
+        var emitted = instance.ExpectMsg<AlarmStateChanged>();
+        Assert.Equal(Source().CanonicalName, emitted.NativeSourceCanonicalName);
+        Assert.Equal("Pressure", emitted.NativeSourceCanonicalName);
+    }
+
     [Fact]
     public void SnapshotComplete_WithMissingPriorAlarm_EmitsReturnToNormal()
     {