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.

src/ZB.MOM.WW.ScadaBridge.Commons/Messages/Streaming/AlarmStateChanged.cs

@@ -71,4 +71,18 @@ public record AlarmStateChanged(
 
     /// <summary>Limit/threshold value for native limit alarms (display-only); empty otherwise.</summary>
     public string LimitValue { get; init; } = string.Empty;
+
+    /// <summary>
+    /// Canonical name of the native alarm SOURCE BINDING this condition belongs to
+    /// (e.g. "Motor1.MotorAlarms"). Lets the Debug View nest live native conditions
+    /// under their configured binding node. Empty for computed alarms. Additive.
+    /// </summary>
+    public string NativeSourceCanonicalName { get; init; } = string.Empty;
+
+    /// <summary>
+    /// True when this row is a placeholder emitted for a CONFIGURED native source
+    /// binding that currently has no active conditions, so the Debug View tree can
+    /// show the binding node as "no active conditions". Additive; default false.
+    /// </summary>
+    public bool IsConfiguredPlaceholder { get; init; }
 }