Port: 9001 (public) - Called by Auth0 Post-Registration Action.
This endpoint is triggered by Auth0 immediately after a user completes registration. It creates the user record in the local database with their Auth0 information.
Authentication: Secured with Auth0 webhook secret via custom header.
Important: Always returns 200 OK to prevent Auth0 from retrying, even on errors. This prevents duplicate registration attempts and information leakage.
Auth0 webhook secret for authenticating webhook requests. For local development only, use 'dev-bypass' to skip authentication.
Webhook received and processed (or acknowledged with error logged)