feat(GWC-37,WRK-32): refresh live alarm watch lists

src/ZB.MOM.WW.MxGateway.Worker.Tests/MxAccess/AlarmCommandExecutorTests.cs

@@ -91,6 +91,27 @@ public sealed class AlarmCommandExecutorTests
         Assert.Equal(ProtocolStatusCode.InvalidRequest, reply.ProtocolStatus.Code);
     }
 
+    /// <summary>Verifies that a live watch-list replacement routes to the alarm handler on the executor thread.</summary>
+    [Fact]
+    public void UpdateAlarmWatchList_WithHandler_RoutesToHandlerAndReturnsOk()
+    {
+        FakeAlarmHandler handler = new FakeAlarmHandler();
+        MxAccessCommandExecutor executor = NewExecutor(handler);
+        var target = new AlarmSubtagTarget { AlarmFullReference = "Galaxy!Area.Tank01.Alarm" };
+
+        MxCommandReply reply = executor.Execute(new StaCommand(
+            SessionId,
+            CorrelationId,
+            new MxCommand
+            {
+                Kind = MxCommandKind.UpdateAlarmWatchList,
+                UpdateAlarmWatchList = new UpdateAlarmWatchListCommand { WatchList = { target } },
+            }));
+
+        Assert.Equal(ProtocolStatusCode.Ok, reply.ProtocolStatus.Code);
+        Assert.Equal(target, Assert.Single(handler.LastWatchList!));
+    }
+
     /// <summary>Verifies that acknowledge routes native status into hresult and payload.</summary>
     [Fact]
     public void AcknowledgeAlarm_WithHandler_RoutesNativeStatusIntoHresultAndPayload()
@@ -447,6 +468,15 @@ public sealed class AlarmCommandExecutorTests
             LastSessionId = sessionId;
         }
 
+        /// <summary>Gets the most recent replacement watch list.</summary>
+        public IReadOnlyList<AlarmSubtagTarget>? LastWatchList { get; private set; }
+
+        /// <inheritdoc />
+        public void UpdateWatchList(IReadOnlyList<AlarmSubtagTarget> watchList)
+        {
+            LastWatchList = watchList;
+        }
+
         /// <inheritdoc />
         public void Unsubscribe()
         {