implement auth login and register with MongoDB

- Add AuthController login/register endpoints with error handling
- Implement AuthService with password validation and user creation
- Add MongoUserRepository with findByEmail and create methods
- Implement password hashing with bcrypt
- Add dotenv for environment variable support
- Add Docker Compose setup for MongoDB + Mongo Express
- Stub AuthMiddleware with fake user for testing
- Update CLAUDE.md with implementation status

docs/api-routes.md

@@ -0,0 +1,54 @@
+# CalChat API Routes
+
+Base URL: `/api`
+
+## Authentication
+
+### Auth Endpoints (`/api/auth`)
+Öffentliche Endpoints - keine Authentifizierung erforderlich.
+
+| Method | Endpoint | Beschreibung |
+|--------|----------|--------------|
+| POST | `/auth/login` | User Login |
+| POST | `/auth/register` | User Registrierung |
+| POST | `/auth/refresh` | JWT Token erneuern |
+| POST | `/auth/logout` | User Logout |
+
+---
+
+## Events
+
+### Event Endpoints (`/api/events`)
+Alle Endpoints erfordern JWT-Authentifizierung.
+
+| Method | Endpoint | Beschreibung |
+|--------|----------|--------------|
+| GET | `/events` | Alle Events des Users abrufen |
+| GET | `/events/range` | Events nach Zeitraum filtern |
+| GET | `/events/:id` | Einzelnes Event abrufen |
+| POST | `/events` | Neues Event erstellen |
+| PUT | `/events/:id` | Event aktualisieren |
+| DELETE | `/events/:id` | Event löschen |
+
+---
+
+## Chat
+
+### Chat Endpoints (`/api/chat`)
+Alle Endpoints erfordern JWT-Authentifizierung.
+
+| Method | Endpoint | Beschreibung |
+|--------|----------|--------------|
+| POST | `/chat/message` | Nachricht an AI senden |
+| POST | `/chat/confirm/:conversationId/:messageId` | Vorgeschlagenes Event bestätigen |
+| POST | `/chat/reject/:conversationId/:messageId` | Vorgeschlagenes Event ablehnen |
+| GET | `/chat/conversations` | Alle Konversationen abrufen |
+| GET | `/chat/conversations/:id` | Nachrichten einer Konversation (mit Pagination) |
+
+---
+
+## Health
+
+| Method | Endpoint | Beschreibung |
+|--------|----------|--------------|
+| GET | `/health` | Health Check |