Add shareable QR payment system to rCart:
- PaymentRequestDoc schema with amountEditable support
- Payment API routes (create, list, get, update, QR SVG, Transak session)
- folk-payment-page: 3-tab payer view (Card/Wallet/EncryptID passkey)
- folk-payment-request: self-service QR generator with passkey auth
- Payments tab in folk-cart-shop for managing requests
- Extract Transak utils to shared/transak.ts (used by rFlows + rCart)
Routes: /:space/rcart/request (generator), /:space/rcart/pay/:id (payer)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Jeff Emmett
c049d7e8df