Who owns the Dispatch account after an agency hands off a client site?

The client. A client site belongs in the client's own Dispatch organization from the start, with agency staff invited as members, so ownership never has to be transferred out of the agency's account. At handoff the client holds the owner role, every repository, host, and Slack token is rotated to one the client controls, and the agency keeps whatever role the engagement calls for: admin to keep operating, editor to keep filing requests, or a standing escalation contact with no seat at all. The client's team lands on the Inbox and approves; the record, restore, and the alerts stay with the site.