Fix production auth by proxying /api to backend in remote builds.

Remote frontend nginx now forwards API requests to Django so login and registration work when the host proxy only routes to port 8080.

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

docker-compose.prod.yml

@@ -9,6 +9,10 @@ services:
     ports:
       - "${FRONTEND_BIND:-127.0.0.1}:${FRONTEND_PORT:-8080}:80"
     restart: unless-stopped
+    depends_on:
+      backend:
+        condition: service_started
+        required: false
 
   backend:
     profiles: ["with-backend"]