Harden render server and import boundaries

docker-compose.yml

@@ -2,9 +2,14 @@ services:
   animatr-render:
     build: ./server
     ports:
-      - "6000:6000"
+      - "127.0.0.1:6000:6000"
     environment:
       - NODE_ENV=production
       - PORT=6000
+      - HOST=0.0.0.0
+      - RENDER_TOKEN=${RENDER_TOKEN:?set RENDER_TOKEN before starting the render server}
     shm_size: "2gb"
+    pids_limit: 256
+    mem_limit: 2g
+    cpus: 2
     restart: unless-stopped