A seat that cannot remove a tag alone (another tag names its digest) now answers and says kept. The builder ends that remove there, with no retry, and marks the version kept on its store with the reason and the other tags; builder_versions shows it, and a later branch end asks it no more. The four seats' kept are consumed. Claude-Session: https://claude.ai/code/session_01JG73KJNrH5EgFXMKKYSrig