The admin_notifications.booking_id FK has no ON DELETE CASCADE, so hard-deleting a booking with existing notifications fails with a FK constraint violation. Fix by explicitly deleting related notifications before the booking DELETE. Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent) Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>