get_device_warnings() now reports lldpd_not_installed (action
install_lldpd) when lldpd is absent, matching the existing
OpenWrt pattern. run_device_action("install_lldpd") installs and
enables lldpd via apt/systemd so LLDP topology links to directly
connected switches can be discovered.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>