Build a Subscription Membership App (React + Supabase + Stripe) — Spec & Designs Ready

I'm building a subscription membership web app. Members pay an annual fee and unlock member-only pricing at partner businesses. I have a complete spec and mockups (the design source of truth), plus a data template and a partner intake form. Stack: React (Vite) + Tailwind, Supabase Auth, Stripe for the subscription (Checkout + Customer Portal + a webhook that syncs status to Supabase), hosted on Vercel. The parts that need real experience: the Stripe→Supabase webhook sync, a per-member 12-month term derived from the Stripe subscription, seasonal "intro vs. repeat" pricing windows, and a simple admin flow to add new partners.