fix(ui): refresh alert config on WebSocket reconnection

Fixes issue where alert toggle appears disabled after connection loss.
- Add websocket_reconnected event to event bus
- Emit event when WebSocket successfully reconnects
- App subscribes and refreshes alert activation state on reconnection

frontend-modern/src/App.tsx

@@ -486,15 +486,26 @@ function App() {
       }
     };
 
-    // Subscribe to theme change events
+    // Handle WebSocket reconnection - refresh alert config to restore activation state
+    // This fixes issue where alert toggle appears disabled after connection loss
+    const handleWebSocketReconnected = () => {
+      logger.info('WebSocket reconnected, refreshing alert configuration');
+      void alertsActivation.refreshConfig();
+      void alertsActivation.refreshActiveAlerts();
+    };
+
+    // Subscribe to events
     eventBus.on('theme_changed', handleThemeChange);
+    eventBus.on('websocket_reconnected', handleWebSocketReconnected);
 
     // Cleanup on unmount
     onCleanup(() => {
       eventBus.off('theme_changed', handleThemeChange);
+      eventBus.off('websocket_reconnected', handleWebSocketReconnected);
     });
   });
 
+
   // Check auth on mount
   onMount(async () => {
     logger.debug('[App] Starting auth check...');

frontend-modern/src/stores/events.ts

@@ -6,7 +6,8 @@ export type EventType =
   | 'refresh_nodes'
   | 'discovery_updated'
   | 'discovery_status'
-  | 'theme_changed';
+  | 'theme_changed'
+  | 'websocket_reconnected';
 
 // Event data types
 export interface NodeAutoRegisteredData {
@@ -51,6 +52,7 @@ export type EventDataMap = {
   discovery_updated: DiscoveryUpdatedData;
   discovery_status: DiscoveryStatusData;
   theme_changed: string; // 'light' or 'dark'
+  websocket_reconnected: void; // Emitted when WebSocket successfully reconnects
 };
 
 // Generic event handler

frontend-modern/src/stores/websocket.ts

@@ -308,6 +308,7 @@ export function createWebSocketStore(url: string) {
 
     ws.onopen = () => {
       logger.debug('connect');
+      const wasReconnecting = reconnectAttempt > 0;
       setConnected(true);
       setReconnecting(false); // Clear reconnecting state
       reconnectAttempt = 0; // Reset reconnect attempts on successful connection
@@ -329,9 +330,17 @@ export function createWebSocketStore(url: string) {
         }
       }, heartbeatIntervalMs);
 
+      // Emit reconnection event so App can refresh alert config
+      // This ensures the alert activation state is re-fetched after connection loss
+      if (wasReconnecting) {
+        logger.info('WebSocket reconnected, emitting event for config refresh');
+        eventBus.emit('websocket_reconnected');
+      }
+
       // Alerts will come with the initial state broadcast
     };
 
+
     ws.onmessage = (event) => {
       let data;
       try {