networkmanager, systemd-networkd and dhcpcd each claim the-uplink and
declare only what keeps the machine's own network manager from
contradicting the mesh: the resolver file left to resolv-conf, mesh0
left alone. Never a link, profile or credential — the link is the
mesh's only channel to the machine, so NetworkManager and networkd are
reloaded on a change, never restarted, and dhcpcd (no reload; a restart
drops the address) takes its block at its next start.