A host-network sidecar reaches its service over the machine's loopback, and
the mesh publishes that service on a machine port it assigns (ADR 0038) —
so dialling the software's port reaches whatever else holds it. On ace,
searxng's sidecar dialled 127.0.0.1:8080 and got unifi's inform port. The
same shape in bazarr, bookshelf, lidarr, nzbget, qbittorrent, radarr and
sonarr; each now asks with ${port:N} (hq 088). Found in review of ace's
module preparation.