A trunk image is written as an OCI layout and published by the seat's publish and publish-part, only the parts the holder lacks; an upstream copy is the seat's mirror, ended on the holder's published or refused. The module holds no registry address: artifact-store, files/registry and the copier go, and the step answers the seat's reference. Claude-Session: https://claude.ai/code/session_01JG73KJNrH5EgFXMKKYSrig