A vouched reservation is finished by `Registry::admit`. The owner's record is mirrored into the server's own repository, keyed by the host's hostname; the walk verifies that edge, records the server as the host's parent and registers the host's key. A context the host attests with that key is admitted beneath the host before anything is published, and a host admits what its own key signed for alone. `QueueFull` is the name a full reservation queue refuses with. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> Change-Id: I9c7f42cba4efc2b54c9dada71ef35ca79abbde57