Release commands now work from anywhere: on_repo_host (the published database
living in this checkout) routes build triggers, advances, and promotion to
local execution; other machines go over ssh to the configured destination.
The host setting is any ssh destination — root@<ip>, root@<hostname>, or an
~/.ssh/config alias — resolved from --host, OMARCHY_REPO_HOST, then the
one-line .repo-host file. doctor reports which mode applies, and the README
documents the format and precedence. All host connections are plain ssh.