Put data classes in models folder

lib/data/models/game_manager.dart

@@ -0,0 +1,41 @@
+import 'package:cabo_counter/data/models/game_session.dart';
+import 'package:cabo_counter/services/local_storage_service.dart';
+import 'package:flutter/foundation.dart';
+
+class GameManager extends ChangeNotifier {
+  List<GameSession> gameList = [];
+
+  /// Adds a new game session to the list and sorts it by creation date.
+  /// Takes a [GameSession] object as input. It then adds the session to the `gameList`,
+  /// sorts the list in descending order based on the creation date, and notifies listeners of the change.
+  /// It also saves the updated game sessions to local storage.
+  /// Returns the index of the newly added session in the sorted list.
+  Future<int> addGameSession(GameSession session) async {
+    session.addListener(() {
+      notifyListeners(); // Propagate session changes
+    });
+    gameList.add(session);
+    print(
+        '[game_manager.dart] Added game session: ${session.gameTitle} at ${session.createdAt}');
+    gameList.sort((a, b) => b.createdAt.compareTo(a.createdAt));
+    print(
+        '[game_manager.dart] Sorted game sessions by creation date. Total sessions: ${gameList.length}');
+    notifyListeners();
+    await LocalStorageService.saveGameSessions();
+    print('[game_manager.dart] Saved game sessions to local storage.');
+    return gameList.indexOf(session);
+  }
+
+  /// Removes a game session from the list and sorts it by creation date.
+  /// Takes a [index] as input. It then removes the session at the specified index from the `gameList`,
+  /// sorts the list in descending order based on the creation date, and notifies listeners of the change.
+  /// It also saves the updated game sessions to local storage.
+  void removeGameSession(int index) {
+    gameList[index].removeListener(notifyListeners);
+    gameList.removeAt(index);
+    notifyListeners();
+    LocalStorageService.saveGameSessions();
+  }
+}
+
+final gameManager = GameManager();