A process publishes on mesh.seat.<seat>.accept.<kind>.<caller>, its module the caller, as Emit publishes an event, so the
gate's channel over a connection can ask and cancel through the seat operator-channel.
Builds: design 47 G §677, §700; lead answers A-272, A-273
Claude-Session: https://claude.ai/code/session_01NcbgfGKaxw984XyAPfLm4h