Extract init-neutral unit resolution into service/, add initsys.Init with systemd, openrc and runit backends, selected by 'init:' config or autodetect. OpenRC and runit are root only; rootless units run as system services as that user. Add docs and generated examples for all three.
- startall now uses systemctl start (not enable --now)
- stopall now uses systemctl stop (not disable --now)
- add installall command (bulk install with --dry-run support)
- add uninstallall command (bulk disable+remove in reverse order)
- fix docker ExecStart to use -a flag so the process stays attached
- prefix ExecStop with - so a stop-on-already-dead container does not fail the unit