Add so-nic-pin, which writes by-MAC persistent-net udev rules pinning each
physical NIC to its current name so a kernel upgrade can't renumber the
interfaces Security Onion binds by name (host:mainint, sensor:mainint, bond0).
Gated by the drop file /opt/so/state/nic_names_pinned: run-once on highstate,
and an admin can pre-create the marker to opt out. Wired into common/init.sls
as pin_nic_names, guarded by a matching unless.
Mike Reeves