Use GHCR image for relay compose so seed VPS pulls published builds.

Seed relay nodes should track CI-published backend images instead of local builds that fail without full monorepo context.

Co-authored-by: Cursor <cursoragent@cursor.com>

docker-compose.relay.yml

@@ -1,9 +1,7 @@
 # Minimal relay-node compose — backend only, no frontend needed.
 services:
   backend:
-    build:
-      context: .
-      dockerfile: ./backend/Dockerfile
+    image: ghcr.io/bigbodycobain/shadowbroker-backend:latest
     container_name: shadowbroker-relay
     ports:
       - "127.0.0.1:8000:8000"