Shopify Order Webhook Email with Rovela (2026): HMAC + Idempotency-Key
Verify X-Shopify-Hmac-SHA256 on the raw body, handle orders/create (and optional fulfillment), and send a Rovela order confirmation with Idempotency-Key = Shopify webhook id or order id. Shopify owns commerce; Rovela delivers. Distinct from Stripe receipt and ecommerce-order-email.