feat(notification): integrate expo-notifications for permission handling and deep linking

- Add expo-notifications dependency and configure with JPush plugin
- Request notification permission on app launch for iOS/Android
- Handle notification taps to navigate to chat or notifications screen
- Add UI to check and request system notification permission in settings
- Refactor background sync: WebSocket disconnects in background, JPush handles push
- Add checkNotificationPermission() and requestNotificationPermission() to jpushService

src/services/core/wsService.ts

@@ -1101,7 +1101,14 @@ class WebSocketService {
     if (this.appStateSubscription) return;
     this.lastAppState = AppState.currentState;
     this.appStateSubscription = AppState.addEventListener('change', (nextState: AppStateStatus) => {
+      // 进入后台时断开 WebSocket，由 JPush 负责后台推送通知
+      if (this.lastAppState === 'active' && nextState.match(/inactive|background/)) {
+        console.log('[WebSocket] App entering background, disconnecting');
+        this.disconnect();
+      }
+      // 回到前台时重连 WebSocket
       if (this.lastAppState.match(/inactive|background/) && nextState === 'active' && !this.isConnected()) {
+        console.log('[WebSocket] App returning to foreground, reconnecting');
         this.reconnectAttempts = 0;
         this.connect();
       }