Deleting a custom domain released its name while services still pointed
at it, leaving them on a namespace the account no longer held.
Deletion now refuses with 412 when a service in the same account uses the
domain or a subdomain, including disabled ones. Service writes revalidate
authorization inside their transaction and hold a shared lock on the
matching registrations, so a delete racing a create cannot strand either.
The dependency lookup is account-scoped: registrations are unique by name,
so another account can hold team.example.com under example.com and its
services are authorized by its own registration.
Prevent unvalidated registrations from reserving domain names indefinitely.
Give pending registrations a 48-hour validation window and clean up expired entries at startup and every 60 minutes. Emit CustomDomainValidationExpired for each deletion and preserve registrations referenced by services.
Reject validation after expiry and prevent concurrent validation from recreating deleted registrations. Normalize domain names with the shared parser before registration.
Migrate existing pending registrations to receive a fresh 48-hour validation window.
Maycon Santos