Fix gateway direct-mode not triggering on VPN disconnect

The gateway-direct-mode.service was never triggering when WireGuard
interfaces were removed, leaving VPN iptables rules active even when
VPN was disconnected. This caused internet connectivity to fail in
direct mode.

Root cause: SYSTEMD_WANTS in udev rules only works for ACTION=="add"
events. When a device is removed, the device unit is already gone
before systemd can process the SYSTEMD_WANTS dependency, so the
service never starts. This is a documented systemd limitation.

Fix: Replace SYSTEMD_WANTS with RUN+ for the remove action, which
executes systemctl directly during udev event processing without
requiring a device unit to exist.

References:
- https://stackoverflow.com/questions/72208534/why-does-systemd-wants-not-pass-a-parameter-to-a-service-file-from-a-udev-remov
- https://stackoverflow.com/questions/73148448/how-to-start-systemd-user-service-when-device-is-removed-and-stop-it-when-devic
- https://bugzilla.redhat.com/show_bug.cgi?id=871074https://bugzilla.redhat.com/show_bug.cgi?id=871074
- https://unix.stackexchange.com/questions/528803/systemd-doesnt-stop-the-service-when-the-device-is-removed

The VPN mode (ACTION=="add") continues to use SYSTEMD_WANTS as it
works correctly for device addition events.

0 files changed, 0 insertions, 0 deletions