Stripe Webhook Receipt Email with Rovela (2026): Signature + Idempotency-Key
Verify Stripe-Signature on the raw body, handle checkout.session.completed / invoice.paid / payment_intent.succeeded, and send a Rovela receipt with Idempotency-Key = Stripe event id. Stripe owns payments; Rovela delivers. Distinct from ecommerce-order and invoice-attachment posts.