marreta: content-cleaning proxy on Dankclaw, gluetun netns, guard-chained

Deploy manualdousuario/marreta (Laravel / serversideup php:8.4-fpm-nginx)
as a rootless Quadlet pair (marreta + marreta-browser/Lightpanda), both
joining gluetun's netns so all fetch egress exits the same ProtonVPN
tunnel as SearXNG.

- marreta relocated to NGINX_HTTP_PORT=8085 (netns already has searxng on
  8080); gluetun publishes 8082:8085; Caddy dials 192.168.0.143:8082.
- Guard chain: marreta.franksdank.cloud -> Anubis :8923 -> Authentik ->
  post-auth :8017 @marreta -> 8082. Access = any authenticated user.
- Secrets seeded to /home/dank/Containers/marreta/env (0600) from
  MARRETA_APP_KEY / MARRETA_ADMIN_EMAIL / MARRETA_ADMIN_PASSWORD.
- deploy-plan.py: marreta joins the gluetun netns family.
- New seam tests/marreta_quadlet.bats (17 contracts); scoping test updated
  for the widened netns family. Doc: Dankclaw/Marreta.md + index + log.

dankclaw/Caddyfile

@@ -152,6 +152,16 @@ seerr.franksdank.cloud {
 	}
 }
 
+# --- Marreta (guarded: Anubis → Authentik; marreta provider, internal_host caddy:8017) ---
+# Content-cleaning proxy. Any authentik-authenticated user may use it (no
+# group gate). Egress rides the searxng gluetun tunnel; reached via the
+# host-published port 8082 (gluetun netns), not by container name.
+marreta.franksdank.cloud {
+	reverse_proxy anubis:8923 {
+		header_up X-Real-Ip {remote_host}
+	}
+}
+
 # --- Pi-hole (quadlet on slirp4netns; published 8083) ---
 pihole.franksdank.cloud {
 	basicauth {
@@ -379,6 +389,11 @@ http://:8017 {
 	handle @qbittorrent {
 		reverse_proxy 192.168.0.112:8080
 	}
+
+	@marreta host marreta.franksdank.cloud
+	handle @marreta {
+		reverse_proxy 192.168.0.143:8082
+	}
 }
 
 # --- Optional: Jackett ---