feat(api): Add user authentication functionality

- Implement JWT-based user authentication logic
- Add login endpoint and token validation middleware
- Update API routes with authentication dependencies
- Add authentication-related environment variables
- Optimize requirements.txt with necessary dependencies

env.example

@@ -148,3 +148,10 @@ QDRANT_URL=http://localhost:16333
 
 ### Redis
 REDIS_URI=redis://localhost:6379
+
+# For jwt auth
+AUTH_USERNAME=admin      # login name
+AUTH_PASSWORD=admin123   # password
+TOKEN_SECRET=your-key # JWT key
+TOKEN_EXPIRE_HOURS=4     # expire duration
+WHITELIST_PATHS=/login,/health  # white list