Fix sidebar alert badge not syncing with sub-tab dismissals

Dashboard/MainWindow.xaml.cs

@@ -445,6 +445,12 @@ private void OpenServerTab(ServerConnection server)
             Helpers.ServerTimeHelper.UtcOffsetMinutes = utcOffset;
 
             var serverTab = new ServerTab(server, utcOffset);
+            serverTab.AlertAcknowledged += (_, _) =>
+            {
+                _emailAlertService.HideAllAlerts(8760, server.DisplayName);
+                UpdateAlertBadge();
+                _alertsHistoryContent?.RefreshAlerts();
+            };
 
             var headerPanel = new StackPanel { Orientation = Orientation.Horizontal };
             var headerText = new TextBlock

Dashboard/ServerTab.xaml.cs

@@ -28,6 +28,12 @@ public partial class ServerTab : UserControl
         private readonly ICredentialService _credentialService;
         private ServerHealthStatus? _lastKnownStatus;
 
+        /// <summary>
+        /// Raised when the user acknowledges a sub-tab alert (Locking, Memory, etc.)
+        /// so the sidebar badge can be updated.
+        /// </summary>
+        public event EventHandler? AlertAcknowledged;
+
         /// <summary>
         /// This server's UTC offset in minutes, used to restore the global
         /// ServerTimeHelper when this tab becomes active.
@@ -3097,6 +3103,8 @@ private void AcknowledgeSubTabAlert_Click(object sender, RoutedEventArgs e)
                     {
                         badge.Visibility = Visibility.Collapsed;
                     }
+
+                    AlertAcknowledged?.Invoke(this, EventArgs.Empty);
                 }
             }
         }