New services/adguard.nix runs AdGuard Home on the mediaserver with DoH
upstreams (Cloudflare + Quad9) and three default blocklists. DNS listens
on :53; web UI on 127.0.0.1:3000, reverse-proxied at adguard.nordhammer.it.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
