Fix & Productionize an AI-Built Web App (React/Next.js + Supabase)

We have a web app built mostly with AI tools (Lovable + Supabase, React/Next.js front end) that works as a demo but isn't production-ready. We need an experienced full-stack engineer to review it, harden it, and get it launch-ready for real users. What's there: a working React/Next.js front end, Supabase (Postgres + Auth), a few API integrations. It runs, but the code is inconsistent, auth/session handling is shaky, and we're not confident it's secure or will hold up as we add users. Scope: - Review the codebase + architecture and give a clear "what's solid / what's risky / what to fix first" breakdown - Harden authentication and session handling (currently a weak spot) - Security pass — data access, API boundaries, anything that shouldn't be exposed - Clean up the AI-generated code into something maintainable - Get it to a stable, deployable v1 without breaking what works You should be strong with React/Next.js, Node.js, Supabase/Postgres, API integration, auth, and application security, and comfortable jumping into an unfamiliar AI-built codebase. In your proposal, please include a short note on a similar AI-built or prototype app you took to production, and how you'd approach the first week. Long-term potential if it goes well.