Site settings -> Webhooks: admins add https endpoints and choose event
types (registration created/paid/cancelled, payment received/refunded,
ticket checked in, account created, event published). Events are
noticed by a Prisma client extension so every write path is covered,
re-checked before sending, and delivered as signed JSON
(X-CrossEvents-Signature, HMAC-SHA256) with retries, a 30-day delivery
log, Send test and Resend. Public https addresses only; each endpoint
is added to the operator register; kids and volunteer tickets are never
sent. New `webhooks` job. Migration 20261028160000_webhooks.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>