Service was crashing on every boot because vetting.example.yaml uses
./var/... relative paths that resolve to / under ProtectSystem=strict.
Ship a separate vetting.production.yaml with absolute /var/lib/vetting
+ /var/log/vetting paths that match the unit's ReadWritePaths, and
have install.sh copy that one. Also move StartLimit* keys into [Unit]
to silence the 'Unknown key' warning on modern systemd.