Move restart-mode prerequisites (systemd unit default, tmux, compose file,
script hook, EVO_SYSTEMD_SCOPE) ahead of git fetch/install/build/migrate.
Explicit systemd with no EVO_SYSTEMD_UNIT falls back to EVO_SYSTEMD_AUTO_UNIT.
die() after checkout triggers rollback; rollback marks in-progress to avoid loops.
Co-authored-by: Cursor Agent <cursoragent@cursor.com>
Co-authored-by: cynarAI <cynarAI@users.noreply.github.com>