added devcontainer with all tools for frontent (deno, nextjs) and backend (dart, go)

backend-dart/lib/application/usecases/register_user.dart

@@ -0,0 +1,19 @@
+import 'package:backend_dart/domain/entities/user.dart';
+import 'package:backend_dart/domain/repositories/user_repository.dart';
+
+class RegisterUserUseCase {
+  final UserRepository userRepository;
+
+  RegisterUserUseCase(this.userRepository);
+
+  Future<void> execute(String name, String email, String password) async {
+    final user = User(
+      id: 'generated-id', // Eine Methode zur ID-Erzeugung einfügen
+      name: name,
+      email: email,
+      password: password, // In der Realität: Passwörter hashen
+    );
+
+    await userRepository.create(user);
+  }
+}