Add FCM push notifications, queue alerts, caller ID fixes, and auto-revert agent status

Server-side:
- Add push credential auto-creation for FCM incoming call notifications
- Add queue alert FCM notifications (data-only for background delivery)
- Add queue alert cancellation on call accept/disconnect
- Fix caller ID to show caller's number instead of Twilio number
- Fix FCM token storage when refresh_token is null
- Add pre_call_status tracking to revert agent status 30s after call ends
- Add SSE fallback polling for mobile app connectivity

Mobile app:
- Add Android telecom permissions and phone account registration
- Add VoiceFirebaseMessagingService for incoming call push handling
- Add insistent queue alert notifications with custom sound
- Fix caller number display on active call screen
- Add caller ID selection dropdown on dashboard
- Add phone numbers endpoint and provider support
- Add unit tests for CallInfo, QueueState, and CallProvider
- Remove local.properties from tracking, add .gitignore

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

mobile/lib/providers/auth_provider.dart

@@ -10,10 +10,10 @@ enum AuthState { unauthenticated, authenticating, authenticated }
 
 class AuthProvider extends ChangeNotifier {
   final ApiClient _apiClient;
-  late final AuthService _authService;
-  late final VoiceService _voiceService;
-  late final PushNotificationService _pushService;
-  late final SseService _sseService;
+  late AuthService _authService;
+  late VoiceService _voiceService;
+  late PushNotificationService _pushService;
+  late SseService _sseService;
 
   AuthState _state = AuthState.unauthenticated;
   User? _user;
@@ -36,8 +36,9 @@ class AuthProvider extends ChangeNotifier {
   }
 
   Future<void> tryRestoreSession() async {
-    final restored = await _authService.tryRestoreSession();
-    if (restored) {
+    final user = await _authService.tryRestoreSession();
+    if (user != null) {
+      _user = user;
       _state = AuthState.authenticated;
       await _initializeServices();
       notifyListeners();
@@ -67,7 +68,7 @@ class AuthProvider extends ChangeNotifier {
       debugPrint('AuthProvider: push service init error: $e');
     }
     try {
-      await _voiceService.initialize();
+      await _voiceService.initialize(deviceToken: _pushService.fcmToken);
     } catch (e) {
       debugPrint('AuthProvider: voice service init error: $e');
     }
@@ -96,10 +97,18 @@ class AuthProvider extends ChangeNotifier {
   }
 
   void _handleForceLogout() {
+    _voiceService.dispose();
+    _sseService.disconnect();
+
     _state = AuthState.unauthenticated;
     _user = null;
     _error = 'Session expired. Please log in again.';
-    _sseService.disconnect();
+
+    // Re-create services for potential re-login
+    _voiceService = VoiceService(_apiClient);
+    _pushService = PushNotificationService(_apiClient);
+    _sseService = SseService(_apiClient);
+
     notifyListeners();
   }