some cleanup and some fixes

lib/main.dart

@@ -5,12 +5,12 @@ import 'package:provider/provider.dart';
 import 'package:flutter_dotenv/flutter_dotenv.dart';
 import 'src/services/deck_repository.dart';
 import 'src/screens/start_screen.dart';
+import 'src/services/tts_service.dart';
 
 void main() async {
   WidgetsFlutterBinding.ensureInitialized();
   try {
     await dotenv.load(fileName: ".env");
-    // No need to catch because the file is only needed for dev
   } catch (_) {}
 
   runApp(
@@ -19,6 +19,14 @@ void main() async {
         Provider<DeckRepository>(create: (_) => DeckRepository()),
         Provider<VocabDeckRepository>(create: (_) => VocabDeckRepository()),
         ChangeNotifierProvider<ThemeModel>(create: (_) => ThemeModel()),
+        Provider<TtsService>(
+          create: (_) {
+            final ttsService = TtsService();
+            ttsService.initTts();
+            return ttsService;
+          },
+          dispose: (_, ttsService) => ttsService.dispose(),
+        ),
       ],
       child: const WkApp(),
     ),