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

apps/server/docker/mongo/compose.yml

@@ -0,0 +1,33 @@
+services:
+  mongo:
+    image: mongo:8
+    restart: always
+    ports:
+      - "27017:27017"
+    environment:
+      MONGO_INITDB_ROOT_USERNAME: root
+      MONGO_INITDB_ROOT_PASSWORD: mongoose
+    volumes:
+      - mongo-data:/data/db
+    healthcheck:
+      test: mongosh --eval "db.adminCommand('ping')"
+      interval: 10s
+      timeout: 5s
+      retries: 5
+
+  mongo-express:
+    image: mongo-express:latest
+    restart: always
+    ports:
+      - "8081:8081"
+    environment:
+      ME_CONFIG_MONGODB_URL: mongodb://root:mongoose@mongo:27017/
+      ME_CONFIG_BASICAUTH_ENABLED: true
+      ME_CONFIG_BASICAUTH_USERNAME: admin
+      ME_CONFIG_BASICAUTH_PASSWORD: admin
+    depends_on:
+      mongo:
+        condition: service_healthy
+
+volumes:
+  mongo-data: