Replace Stripe checkout with Mollie payments API. Mollie handles
payment method selection on their hosted checkout (card, SEPA, iDEAL,
PayPal, etc). Simpler auth model — single API key, no webhook secrets.
- Rewrite /api/create-checkout-session for Mollie payment creation
- Rewrite /api/webhook for Mollie status verification flow
- Update google-sheets.ts: stripeSessionId → paymentSessionId
- Remove payment method radio buttons (Mollie shows all methods)
- Update docker-compose env vars
- Swap stripe npm package for @mollie/api-client
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Jeff Emmett