seerr: quadlet on dankclaw + guard-chain vhost + deployer wiring

Unit: ghcr.io/seerr-team/seerr:v3.4.1, loopback-only 5055 publish
(homepage probe; users go through Anubis->Authentik->caddy:8017->seerr),
Containers data root, no env secrets. Guard chain: seerr.franksdank.cloud
vhost behind anubis:8923 with post-auth handler on 8017; addn-hosts record;
homepage widget; deploy-remote/deploy-plan/deploy.sh routing; seam test.

dankclaw/pihole/addn-hosts

@@ -43,3 +43,4 @@
 192.168.0.143 prometheus.franksdank.cloud
 192.168.0.143 loki.franksdank.cloud
 192.168.0.143 pihole.franksdank.cloud
+192.168.0.143 seerr.franksdank.cloud