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/utils/jwt.ts

@@ -0,0 +1,26 @@
+import jwt from 'jsonwebtoken';
+
+export interface TokenPayload {
+  userId: string;
+  email: string;
+}
+
+export interface JWTConfig {
+  secret: string;
+  expiresIn: string;
+}
+
+const JWT_SECRET = process.env.JWT_SECRET || 'your-secret-key';
+const JWT_EXPIRES_IN = process.env.JWT_EXPIRES_IN || '1h';
+
+export function signToken(payload: TokenPayload): string {
+  throw new Error('Not implemented');
+}
+
+export function verifyToken(token: string): TokenPayload {
+  throw new Error('Not implemented');
+}
+
+export function decodeToken(token: string): TokenPayload | null {
+  throw new Error('Not implemented');
+}