feat(dcl): MxGateway StreamAlarms adapter (snapshot + live transitions, reconnecting)

Adds IAlarmSubscribableConnection to MxGatewayDataConnection (shared session-less
feed, ref-counted), IMxGatewayClient.RunAlarmStreamAsync over the package
StreamAlarmsAsync with internal reconnect, and MxGatewayAlarmMapper
(AlarmFeedMessage/OnAlarmTransitionEvent -> NativeAlarmTransition). Behavior
verified against a live gateway in Task 28; mapper unit-tested.

src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/Adapters/IMxGatewayClient.cs

@@ -1,4 +1,5 @@
 using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Protocol;
+using ZB.MOM.WW.ScadaBridge.Commons.Types.Alarms;
 
 namespace ZB.MOM.WW.ScadaBridge.DataConnectionLayer.Adapters;
 
@@ -69,6 +70,17 @@ public interface IMxGatewayClient : IAsyncDisposable
     /// <param name="onUpdate">Callback invoked per advised-tag value change.</param>
     /// <param name="ct">Cancellation token; ends the loop when cancelled.</param>
     Task RunEventLoopAsync(Action<MxValueUpdate> onUpdate, CancellationToken ct = default);
+
+    /// <summary>
+    /// Long-running consumer of the gateway's session-less StreamAlarms feed. Emits a
+    /// Snapshot…SnapshotComplete replay of active alarms then live transitions. Re-opens
+    /// the stream internally on transport faults (the source replays a fresh snapshot).
+    /// Completes only when <paramref name="ct"/> is cancelled.
+    /// </summary>
+    /// <param name="alarmFilterPrefix">Optional source-reference prefix to scope the feed; null = gateway-wide.</param>
+    /// <param name="onTransition">Callback invoked per native alarm transition.</param>
+    /// <param name="ct">Cancellation token; ends the loop when cancelled.</param>
+    Task RunAlarmStreamAsync(string? alarmFilterPrefix, Action<NativeAlarmTransition> onTransition, CancellationToken ct = default);
 }
 
 /// <summary>Builds <see cref="IMxGatewayClient"/> instances.</summary>