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/services/voice_service.dart

@@ -1,4 +1,6 @@
 import 'dart:async';
+import 'dart:io';
+import 'package:dio/dio.dart';
 import 'package:flutter/foundation.dart';
 import 'package:twilio_voice/twilio_voice.dart';
 import 'api_client.dart';
@@ -7,6 +9,8 @@ class VoiceService {
   final ApiClient _api;
   Timer? _tokenRefreshTimer;
   String? _identity;
+  String? _deviceToken;
+  StreamSubscription? _eventSubscription;
 
   final StreamController<CallEvent> _callEventController =
       StreamController<CallEvent>.broadcast();
@@ -14,11 +18,30 @@ class VoiceService {
 
   VoiceService(this._api);
 
-  Future<void> initialize() async {
+  Future<void> initialize({String? deviceToken}) async {
+    _deviceToken = deviceToken;
+    debugPrint('VoiceService.initialize: deviceToken=${deviceToken != null ? "present (${deviceToken.length} chars)" : "NULL"}');
+
+    // Request permissions (Android telecom requires these)
+    await TwilioVoice.instance.requestMicAccess();
+    if (!kIsWeb && Platform.isAndroid) {
+      await TwilioVoice.instance.requestReadPhoneStatePermission();
+      await TwilioVoice.instance.requestReadPhoneNumbersPermission();
+      await TwilioVoice.instance.requestCallPhonePermission();
+      await TwilioVoice.instance.requestManageOwnCallsPermission();
+      // Register phone account with Android telecom
+      // (enabling is handled by dashboard UI with a user-friendly dialog)
+      await TwilioVoice.instance.registerPhoneAccount();
+    }
+
+    // Fetch token and register
     await _fetchAndRegisterToken();
 
-    TwilioVoice.instance.callEventsListener.listen((event) {
-      _callEventController.add(event);
+    // Listen for call events (only once)
+    _eventSubscription ??= TwilioVoice.instance.callEventsListener.listen((event) {
+      if (!_callEventController.isClosed) {
+        _callEventController.add(event);
+      }
     });
 
     // Refresh token every 50 minutes
@@ -35,9 +58,13 @@ class VoiceService {
       final data = response.data;
       final token = data['token'] as String;
       _identity = data['identity'] as String;
-      await TwilioVoice.instance.setTokens(accessToken: token);
+      await TwilioVoice.instance.setTokens(
+        accessToken: token,
+        deviceToken: _deviceToken ?? 'no-fcm',
+      );
     } catch (e) {
       debugPrint('VoiceService._fetchAndRegisterToken error: $e');
+      if (e is DioException) debugPrint('  response: ${e.response?.data}');
     }
   }
 
@@ -69,11 +96,14 @@ class VoiceService {
       if (callerId != null && callerId.isNotEmpty) {
         extraOptions['CallerId'] = callerId;
       }
-      return await TwilioVoice.instance.call.place(
+      debugPrint('VoiceService.makeCall: to=$to, from=$_identity, extras=$extraOptions');
+      final result = await TwilioVoice.instance.call.place(
         to: to,
         from: _identity ?? '',
         extraOptions: extraOptions,
       ) ?? false;
+      debugPrint('VoiceService.makeCall: result=$result');
+      return result;
     } catch (e) {
       debugPrint('VoiceService.makeCall error: $e');
       return false;
@@ -84,6 +114,17 @@ class VoiceService {
     await TwilioVoice.instance.call.sendDigits(digits);
   }
 
+  Future<List<Map<String, dynamic>>> getQueueCalls(int queueId) async {
+    final response = await _api.dio.get('/queues/$queueId/calls');
+    return List<Map<String, dynamic>>.from(response.data['calls'] ?? []);
+  }
+
+  Future<void> acceptQueueCall(String callSid) async {
+    await _api.dio.post('/calls/$callSid/accept', data: {
+      'client_identity': _identity,
+    });
+  }
+
   Future<void> holdCall(String callSid) async {
     await _api.dio.post('/calls/$callSid/hold');
   }
@@ -98,6 +139,8 @@ class VoiceService {
 
   void dispose() {
     _tokenRefreshTimer?.cancel();
+    _eventSubscription?.cancel();
+    _eventSubscription = null;
     _callEventController.close();
   }
 }