* daemon(systemd): fall back to machine user scope when user bus is missing
* test(systemd): cover machine scope fallback for user-bus errors
* test(systemd): reset execFile mock state across cases
* test(systemd): make machine-user fallback assertion portable
* fix(daemon): keep root sudo path on direct user scope
* test(systemd): cover sudo root user-scope behavior
* ci: use resolvable bun version in setup-node-env