init project setup of the backend with dart and go as well as the frontend with nextjs

backend_dart/lib/domain/entities/user.dart

@@ -0,0 +1,13 @@
+class User {
+  final String id;
+  final String name;
+  final String email;
+  final String password;
+
+  User({
+    required this.id,
+    required this.name,
+    required this.email,
+    required this.password,
+  });
+}

backend_dart/lib/domain/repositories/user_repository.dart

@@ -0,0 +1,7 @@
+import 'package:backend_dart/domain/entities/user.dart';
+
+abstract class UserRepository {
+  Future<void> create(User user);
+  Future<User?> findByEmail(String email);
+  Future<User?> findById(String id);
+}