feat: migrate prosappco from Firebase to NestJS REST API (Fase 2)

- Replace all Firebase* repositories with Api* repositories using HTTP + SharedPreferences JWT
- Remove Firebase.initializeApp() and firebase_messaging background handler from main.dart
- Update DI (app_di.dart) to inject Api* repositories instead of Firebase* ones
- Replace all Timestamp/cloud_firestore usage with ISO 8601 String dates
- Stub PhoneVerificationService (Firebase phone OTP → backend OTP when implemented)
- Add ApiService singleton with JWT management in lib/services/
- Legacy firebase_*_repository.dart files preserved for Fase 4 cleanup

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

lib/local_notifications/local_notifications.dart

@@ -1,6 +1,7 @@
 import 'package:flutter_local_notifications/flutter_local_notifications.dart';
 import 'package:http/http.dart' as http;
 import 'dart:convert';
+import 'package:prosappco/constansts.dart' show API_BASE_URL;
 
 class LocalNotifications {
   static Future<void> requestPermissionLocalNotifications() async {
@@ -76,25 +77,14 @@ class LocalNotifications {
       String token, String title, String body) async {
     try {
       http.Response response = await http.post(
-        Uri.parse('https://fcm.googleapis.com/fcm/send'),
+        Uri.parse('$API_BASE_URL/notifications/send'),
         headers: <String, String>{
           'Content-Type': 'application/json; charset=UTF-8',
-          'Authorization':
-              'key=AAAAORdR-xU:APA91bF_wblg86jHAC-uexrXPHavYRlk5wge1Gf46m56V4J2D2L37Cp_hf46JZUzpvsWPSpqc5ewHelKI9LTifUG_s2mciMI6e5VLKo7E1R8btbNo7iaM9do2ctoyHKUm1atlZBdKaN2',
         },
         body: jsonEncode(
           <String, dynamic>{
-            'notification': <String, dynamic>{
-              'body': body,
-              'title': title,
-              
-            },
-            'priority': 'high',
-            'data': <String, dynamic>{
-              'click_action': 'FLUTTER_NOTIFICATION_CLICK',
-              'id': '1',
-              'status': 'done',
-            },
+            'title': title,
+            'body': body,
             'to': token,
           },
         ),