Deploy Vibe & Supabase App

I have a React project built through Hostinger’s Vibe Coding environment that already talks smoothly to a fully-configured Supabase back-end. What I now need is for the whole stack to live on Vercel—or another similarly priced serverless host—without sacrificing the speed, security, or future growth of the application.

At the moment the codebase already handles user authentication, real-time updates, and file storage via Supabase. All environment variables are ready; the missing piece is a rock-solid deployment workflow and hosting setup that can scale on demand while keeping attack surfaces tight and response times low.

Your mission is to take the existing repository, set up continuous deployment to Vercel (or propose an equivalent platform), tune the build for performance, and harden the configuration so that rate limiting, CORS, headers, and Supabase service roles are correctly enforced. Please also optimise cold-start times and make sure database calls remain efficient under load.

Deliverables
• Production-ready deployment running on Vercel (or agreed platform)
• Automated CI/CD pipeline linked to the main branch
• Performance and security checks in place (headers, secrets management, SSR/ISR settings, edge caching where relevant)
• Short hand-off doc outlining how to roll back, scale up, and monitor the app

Acceptance criteria
The site must cold-start in under two seconds, pass basic penetration scans with zero critical issues, and handle a burst test of 500 concurrent users while maintaining functional real-time updates and file uploads. Once these metrics are met and the documentation is delivered, the project is complete.