arr fleet: FrankBook-Pro is the sole deployment, all egress VPN-gated

FrankBook-Pro becomes the only *arr/qBittorrent deployment. Every fleet
container (qB + five arrs) now shares gluetun's netns, so all egress —
torrent, indexer APIs, metadata lookups — exits the WireGuard tunnel by
construction (AllowedIPs=0.0.0.0/0); the arrs' own ports publish on the
gluetun unit, none on the arr units themselves.

- dankserver/compose.yaml: remove the six arr services (the Aug 20 compose
  copy — never healthy, superseded; config dirs trashed on the host)
- dankclaw/Caddyfile + shared/homepage/services.json: arr vhosts and
  probes repoint 192.168.0.235 -> 192.168.0.112 (FrankBook-Pro)
- frankbook-pro units: five arrs join gluetun netns (Wants/After/Network);
  gluetun publishes 9696/8989/7878/8686/8787 alongside 8080/6881
- tests/frankbook_quadlet.bats: new VPN egress seam — every arr+qB unit
  must share gluetun's netns and publish no port; gluetun must publish the
  whole fleet's ports
- deploy-plan.py: gluetun changes carry the whole netns family (a gluetun
  recreation kills all six joiners); dankserver compose set loses the arrs
- AGENTS.md: deployment is complete only when unit tests AND the Playwright
  E2E suite both pass

tests/deployment_scoping.bats

@@ -111,11 +111,11 @@ REMOTE_DEPLOY="$REPO_ROOT/scripts/deploy-remote.sh"
     [ "$output" = $'gitea-postgres\ngitea-server' ]
 }
 
-@test "frankbook-pro gluetun changes carry qbittorrent; arr changes stay scoped" {
+@test "frankbook-pro gluetun changes carry the whole netns family; arr changes stay scoped" {
     run python3 "$PLANNER" --target frankbook-pro --paths \
         frankbook-pro/gluetun/quadlet/gluetun.container
     [ "$status" -eq 0 ]
-    [ "$output" = $'gluetun\nqbittorrent' ]
+    [ "$output" = $'gluetun\nprowlarr\nqbittorrent\nradarr\nsonarr\nlidarr\nreadarr' ]
     run python3 "$PLANNER" --target frankbook-pro --paths \
         frankbook-pro/sonarr/quadlet/sonarr.container
     [ "$status" -eq 0 ]