channel
move, read and check the pointers versions are deployed behind
genctl channel list <process>
genctl channel set <process> <channel> <version>
genctl channel delete <process> <channel>
genctl channel promote --from <channel> --to <channel> [--process <name>]
genctl channel status [<channel>]
A channel is a named pointer to a version, per process; latest is the one apply moves.
promote copies every pointer from one channel to another, so a deployment moves as one;
—process narrows it to that process and its dependency subtree. status is a coherence
report: it prints only members whose child references are baked at a version the channel
no longer points at.