implement backend skeleton with MongoDB and Claude AI integration

- Add controllers (Auth, Chat, Event) with placeholder implementations
- Add services (Auth, Chat, Event) with business logic interfaces
- Add repositories with MongoDB/Mongoose models (User, Event, Chat)
- Add middleware for JWT authentication
- Add Claude AI adapter implementing AIProvider interface
- Add utility modules for JWT and password handling
- Add shared types and DTOs for User, CalendarEvent, ChatMessage
- Configure routes with proper endpoint structure
- Update app.ts with dependency injection setup
- Add required dependencies: mongoose, bcrypt, jsonwebtoken, @anthropic-ai/sdk

apps/server/src/controllers/ChatController.ts

@@ -0,0 +1,27 @@
+import { Response } from 'express';
+import { ChatService } from '../services';
+import { AuthenticatedRequest } from '../middleware';
+
+export class ChatController {
+  constructor(private chatService: ChatService) {}
+
+  async sendMessage(req: AuthenticatedRequest, res: Response): Promise<void> {
+    throw new Error('Not implemented');
+  }
+
+  async confirmEvent(req: AuthenticatedRequest, res: Response): Promise<void> {
+    throw new Error('Not implemented');
+  }
+
+  async rejectEvent(req: AuthenticatedRequest, res: Response): Promise<void> {
+    throw new Error('Not implemented');
+  }
+
+  async getConversations(req: AuthenticatedRequest, res: Response): Promise<void> {
+    throw new Error('Not implemented');
+  }
+
+  async getConversation(req: AuthenticatedRequest, res: Response): Promise<void> {
+    throw new Error('Not implemented');
+  }
+}