feat: integrate Firebase Analytics, add Google Maps dependencies, and expose new GA4 metric API endpoints.

lib/main.dart

@@ -17,6 +17,7 @@ import 'package:travel_mate/services/expense_service.dart';
 import 'package:firebase_messaging/firebase_messaging.dart';
 import 'package:travel_mate/services/notification_service.dart';
 import 'package:travel_mate/services/map_navigation_service.dart';
+import 'package:travel_mate/services/analytics_service.dart';
 import 'blocs/auth/auth_bloc.dart';
 import 'blocs/auth/auth_event.dart';
 import 'blocs/theme/theme_bloc.dart';
@@ -146,6 +147,10 @@ class MyApp extends StatelessWidget {
         RepositoryProvider<MapNavigationService>(
           create: (context) => MapNavigationService(),
         ),
+        // Analysis service
+        RepositoryProvider<AnalyticsService>(
+          create: (context) => AnalyticsService(),
+        ),
       ],
       child: MultiBlocProvider(
         providers: [
@@ -206,6 +211,9 @@ class MyApp extends StatelessWidget {
               title: 'Travel Mate',
               navigatorKey: ErrorService.navigatorKey,
               themeMode: themeState.themeMode,
+              navigatorObservers: [
+                context.read<AnalyticsService>().getAnalyticsObserver(),
+              ],
               // Light theme configuration
               theme: ThemeData(
                 colorScheme: ColorScheme.fromSeed(