inventory: real mesh state per host (no more placeholder netbird FQDNs)

Audit against actual netbird+tailscale peer lists:
  - hubris is the only LXC-host on Netbird; only workstations + hubris
    have netbird entries
  - 10 LXCs+VMs have real Tailscale FQDNs: apps, jellyfin, paperless,
    gitea, nextcloud, elementsynapse, sophia, mule-images→muleimage,
    arriman→arr, haos→homeassistant
  - 7 hosts are LAN-only (no mesh block): nfs-export, caddy, claudio-bot,
    authentik, plato, mule-photos-new, zimaos
  - mac-mini's netbird FQDN corrected to the actual peer name
    (mac-mini-234-17.netbird.selfhosted)

Also: bin/homelab host_address() now prefers lan_ip first — universally
reachable from any LAN client and from any Netbird peer via the
192.168.8.0/24 network resource routed through hubris. Mesh FQDNs are
fallbacks for roaming workstations without a fixed lan_ip.

This makes 'homelab status' from republic show all backends 'ok' instead
of falsely reporting them 'down' against unresolvable netbird FQDNs.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

hosts/arriman.yaml

@@ -9,8 +9,8 @@ host: hubris
 pve_id: 122
 lan_ip: 192.168.8.132
 mesh:
-  netbird:
-    fqdn: arriman.netbird.selfhosted
+  tailscale:
+    fqdn: arr
 mesh_globals:
   primary: netbird
   accepted: