perf(dcl): coalesce MxGateway alarm stream reopens across a subscribe burst (review 2026-10-21 02/P3)

src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/DataConnectionFactory.cs

@@ -46,10 +46,11 @@ public class DataConnectionFactory : IDataConnectionFactory
         _loggerFactory = loggerFactory;
         _secretResolver = secretResolver;
         var globalOptions = opcUaGlobalOptions.Value;
-        // Only the MxGateway supervisory-advise window is adapter-level today; the rest of
+        // Only the MxGateway supervisory-advise window and alarm-reopen debounce are adapter-level; the rest of
         // DataConnectionOptions is consumed by the actor, which is constructed elsewhere.
-        var supervisoryAdviseParallelism =
-            (dataConnectionOptions?.Value ?? new DataConnectionOptions()).MxSupervisoryAdviseParallelism;
+        var dcOptions = dataConnectionOptions?.Value ?? new DataConnectionOptions();
+        var supervisoryAdviseParallelism = dcOptions.MxSupervisoryAdviseParallelism;
+        var alarmStreamReopenDebounce = dcOptions.MxAlarmStreamReopenDebounce;
         // The client registration name a connection with a blank ClientName falls back to
         // (review 2026-10-21 02/U1 — the option was bound and validated but never read).
         var mxClientNamePrefix = (mxGatewayGlobalOptions?.Value ?? new MxGatewayGlobalOptions()).ClientNamePrefix;
@@ -70,7 +71,8 @@ public class DataConnectionFactory : IDataConnectionFactory
             _loggerFactory.CreateLogger<MxGatewayDataConnection>(),
             _secretResolver,
             supervisoryAdviseParallelism,
-            mxClientNamePrefix));
+            mxClientNamePrefix,
+            alarmStreamReopenDebounce));
     }
 
     /// <summary>