feat(ads): 네이티브 광고 적용 및 디버그 스위치 이동

lib/main.dart

@@ -4,11 +4,13 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:hive_flutter/hive_flutter.dart';
 import 'package:adaptive_theme/adaptive_theme.dart';
 import 'package:go_router/go_router.dart';
+import 'package:google_mobile_ads/google_mobile_ads.dart';
 import 'package:timezone/data/latest_all.dart' as tz;
 
 import 'core/constants/app_colors.dart';
 import 'core/constants/app_constants.dart';
 import 'core/services/notification_service.dart';
+import 'core/utils/ad_helper.dart';
 import 'domain/entities/restaurant.dart';
 import 'domain/entities/visit_record.dart';
 import 'domain/entities/recommendation_record.dart';
@@ -20,6 +22,10 @@ import 'data/sample/sample_data_initializer.dart';
 void main() async {
   WidgetsFlutterBinding.ensureInitialized();
 
+  if (AdHelper.isMobilePlatform) {
+    await MobileAds.instance.initialize();
+  }
+
   // Initialize timezone
   tz.initializeTimeZones();