Initial commit

lib/domain/repositories/chat_repository.dart

@@ -0,0 +1,16 @@
+import 'package:trainhub_flutter/domain/entities/chat_session.dart';
+import 'package:trainhub_flutter/domain/entities/chat_message.dart';
+
+abstract class ChatRepository {
+  Future<List<ChatSessionEntity>> getAllSessions();
+  Future<ChatSessionEntity?> getSession(String id);
+  Future<ChatSessionEntity> createSession();
+  Future<void> deleteSession(String id);
+  Future<List<ChatMessageEntity>> getMessages(String sessionId);
+  Future<ChatMessageEntity> addMessage({
+    required String sessionId,
+    required String role,
+    required String content,
+  });
+  Future<void> updateSessionTitle(String sessionId, String title);
+}