hermes vhost: dial netavark's host address, not the LAN IP (fixes the 502)

hermes-webui is Network=host, so 8787 is a bare host-netns bind, and netavark
DNATs only *published* ports. From Caddy's bridge netns 192.168.0.143:8787 and
10.89.1.1:8787 are both refused, while host.containers.internal:8787
(169.254.1.2) answers 200 — measured live 2026-09-16 from inside the Caddy
container. The dashboard's published 9119 answers on that same LAN IP, which is
what made the old upstream look sound.

The vhost comment asserted "192.168.0.143:8787 is open" from that bridge; it is
not, so the claim is replaced with the measurement, and the hermes-webui quadlet
comment carries the same correction. The seam guarding this invariant accepted
any numeric upstream, so the LAN IP passed it; it now pins the measured-working
form and fails on the LAN IP (teeth verified by substitution).

dankclaw/hermes/quadlet/hermes-webui.container

@@ -16,10 +16,12 @@
 # can drive the browser; a bridge-network client could not reach it at all.
 # The server binds 0.0.0.0:8787 of the host netns, and that is deliberate:
 # this unit is host-networked (the CDP daemon above needs a shared loopback), so
-# Caddy cannot reach it by container name and fronts the guarded vhost
-# hermes.franksdank.cloud with `reverse_proxy 192.168.0.143:8787` (see the
-# hermes block in dankclaw/Caddyfile, which records the same constraint). A
-# loopback bind was tried on 2026-09-16 for a tighter posture and broke that
+# Caddy cannot reach it by container name and fronts the vhost
+# hermes.franksdank.cloud with `reverse_proxy host.containers.internal:8787`
+# (netavark's host address, 169.254.1.2) — not the host LAN IP, which Caddy's
+# bridge netns cannot reach for a bare host-netns bind; the measured asymmetry
+# with published ports is recorded in the hermes block of dankclaw/Caddyfile.
+# A loopback bind was tried on 2026-09-16 for a tighter posture and broke that
 # vhost, because a bind is also the only way an off-host process can reach a
 # host-networked container: the LAN address and the tunnel's localhost hop are
 # both served by the wildcard, and a loopback-only bind serves only the latter.