refactor(caddy): retire decommissioned vhosts, rename chat->ai and jellyfin->jelly

DNS at Porkbun was renamed (chat->ai, jellyfin->jelly) and the qbittorrent,
*arr-stack, comfyui, hermes, dankclaw, and dankserver public records were
deleted. This brings the Caddy config in lockstep: ai/jelly vhosts now match
the new names; comfyui (guarded), hermes (guarded), and the *arr/qb vhosts
are removed as their DNS is gone. The legacy dankclaw/dankserver redirect
vhosts stay: Pi-hole still answers those names on the LAN.

dankclaw/pihole/addn-hosts

@@ -25,7 +25,7 @@
 192.168.0.143 books.franksdank.cloud
 192.168.0.143 romm.franksdank.cloud
 192.168.0.143 files.franksdank.cloud
-192.168.0.143 jellyfin.franksdank.cloud
+192.168.0.143 jelly.franksdank.cloud
 192.168.0.143 radarr.franksdank.cloud
 192.168.0.143 sonarr.franksdank.cloud
 192.168.0.143 lidarr.franksdank.cloud
@@ -36,7 +36,7 @@
 # --- AI / search / dev services (dankclaw, local) ---
 192.168.0.143 search.franksdank.cloud
 192.168.0.143 comfyui.franksdank.cloud
-192.168.0.143 chat.franksdank.cloud
+192.168.0.143 ai.franksdank.cloud
 192.168.0.143 hermes.franksdank.cloud
 192.168.0.143 gitea.franksdank.cloud
 192.168.0.143 grafana.franksdank.cloud