Implemented life cycle listener

lib/main.dart

@@ -1,4 +1,6 @@
+import 'package:cabo_counter/data/game_session.dart';
 import 'package:cabo_counter/utility/apptheme.dart';
+import 'package:cabo_counter/utility/globals.dart';
 import 'package:cabo_counter/utility/local_storage_service.dart';
 import 'package:cabo_counter/views/main_menu_view.dart';
 import 'package:flutter/cupertino.dart';
@@ -6,7 +8,7 @@ import 'package:flutter/cupertino.dart';
 void main() {
   /// FIXME Just for Debugging
   /// Fills the game list with some test data.
-  /*Globals.addGameSession(GameSession(
+  Globals.addGameSession(GameSession(
       gameTitle: 'Spiel am 27.02.2025',
       players: ['Clara', 'Tobias', 'Yannik', 'Lena', 'Lekaia'],
       gameHasPointLimit: true));
@@ -39,13 +41,39 @@ void main() {
       gameTitle: '5 Namen max length',
       players: ['Hartmuth', 'Elisabet', 'Rosalind', 'Theresia', 'Karoline'],
       gameHasPointLimit: false));
-  */
+
   runApp(const App());
 }
 
-class App extends StatelessWidget {
+class App extends StatefulWidget {
   const App({super.key});
 
+  @override
+  State<StatefulWidget> createState() => _AppState();
+}
+
+class _AppState extends State<App> with WidgetsBindingObserver {
+  @override
+  void initState() {
+    super.initState();
+    WidgetsBinding.instance.addObserver(this);
+    LocalStorageService.loadGameSessions();
+  }
+
+  @override
+  void dispose() {
+    WidgetsBinding.instance.removeObserver(this);
+    super.dispose();
+  }
+
+  @override
+  void didChangeAppLifecycleState(AppLifecycleState state) {
+    if (state == AppLifecycleState.paused ||
+        state == AppLifecycleState.detached) {
+      LocalStorageService.saveGameSessions();
+    }
+  }
+
   @override
   Widget build(BuildContext context) {
     LocalStorageService.loadGameSessions();
@@ -64,8 +92,4 @@ class App extends StatelessWidget {
       home: const MainMenuView(),
     );
   }
-
-  dispose() {
-    LocalStorageService.saveGameSessions();
-  }
 }