API rate limiting & Validation middleware

Implement API rate limiting and input validation middleware.

Requirements:

• Add rate limiting (e.g., 100 requests per 15 minutes per IP)
• Implement input validation for all endpoints
• Add CORS middleware for cross-origin requests
• Implement request logging middleware
• Add request/response compression
• Security headers (X-Frame-Options, X-Content-Type-Options, etc.)

Deliverables:

• Rate limiting middleware (express-rate-limit or similar)
• Input validation using Joi or similar library
• CORS configuration
• Request logging setup
• Middleware chain integration in main app