Implement Stripe Checkout in Vue 3 App

I need an intermediate developer to implement Stripe Checkout in my Vue 3 + Vite app.

Flow:
- User completes a quiz
- App initiates Stripe Checkout (£10.99)
- On payment success, Stripe redirects to /payment-success
- That route sets a secure hasPaid=true cookie via Vercel serverless function
- App gates access to /full-report based on that cookie

Requirements:
- Ensure Stripe triggers properly
- Set the cookie securely
- Maintain smooth access control to /full-report

No user login or database involved. Stripe keys and environment are already set up.