Revert "ci: use GitHub Container Registry"

This reverts commit b29b017341.

docker-compose.yml

@@ -30,10 +30,10 @@ services:
 
   app:
     # Production never builds from source — the image is built once by
-    # GitHub Actions on release and pushed to GHCR; this host only
+    # Gitea Actions on release and pushed to the registry; this host only
     # ever pulls a specific, already-tested tag (see deploy.sh, which is the
     # only thing that ever changes ANOUMA_IMAGE in .env).
-    image: ${ANOUMA_IMAGE:-ghcr.io/whitehai11/anouma:latest}
+    image: ${ANOUMA_IMAGE:-git.maro.run/maro/anouma:latest}
     restart: unless-stopped
     networks:
       - anouma-network