purevpn-cli checks `systemctl is-active pured.service` to determine if
components are installed. Without systemd this always returns inactive,
triggering endless sudo/reinstall loop and ETXTBSY when trying to overwrite
the running daemon binary.
Fake systemctl returns "active" when pured is listening on :9485, "inactive"
otherwise. Also handles start/stop/disable/daemon-reload as no-ops.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
