v1.5.0 — Security & Backend Hardening Release

✨ Highlights

• Added rate limiting for URL creation
• Implemented secure ID generation using nanoid
• Hardened backend with Helmet and payload size limits
• Improved URL validation and duplicate prevention
• Zero known npm audit vulnerabilities

🔐 Security

• JWT + cookie-based authentication
• Role-based authorisation (NORMAL / ADMIN)
• Abuse protection via rate limiting

🚀 Deployment

• Railway-ready configuration
• Node.js ≥ 18 recommended