fix(centralui): safe-invoke fire-and-forget calls in AlarmSummary and TreeView (review 2026-10-21 07/M-4)

src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Pages/Monitoring/AlarmSummary.razor

@@ -449,7 +449,7 @@
     private void OnLiveAlarmsChanged(int siteId)
     {
         if (_disposed) return;
-        _ = InvokeAsync(() =>
+        _ = SafeInvokeAsync(() =>
         {
             // Drop stale callbacks for a site we've since navigated away from, and
             // let the poll drive until the aggregator has actually seeded (so we never
@@ -464,6 +464,16 @@
         });
     }
 
+    // Runs the action on the render thread; a callback racing circuit teardown makes
+    // InvokeAsync throw ObjectDisposedException into an otherwise-unobserved task
+    // (pattern from DebugView.SafeInvokeAsync).
+    private async Task SafeInvokeAsync(Action action)
+    {
+        if (_disposed) return;
+        try { await InvokeAsync(action); }
+        catch (ObjectDisposedException) { /* disposed between the guard and the dispatch */ }
+    }
+
     // Rebuilds rows/rollup/visible-rows from the live snapshot. Leaves _notReporting
     // as the last poll computed it (the alarm-only cache can't know it). Idempotent.
     private void ApplyLiveSnapshot(int siteId)