Payment Platform API — Stripe-compatible checkout, payments, and merchant dashboard
API Endpoints
POST /api/auth/register — Create merchant account
POST /api/checkout/sessions — Create checkout session
POST /api/checkout/sessions/:id/confirm — Confirm payment
GET /api/checkout/sessions/:id — Get session
POST /api/payment-intents — Create payment intent
POST /api/refunds — Create refund
POST /api/webhooks — Register webhook endpoint