fix: use relative API path for docker deployment

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docker-compose.yml

@@ -18,12 +18,12 @@ services:
       context: ./frontend
       dockerfile: Dockerfile
       args:
-        - NUXT_PUBLIC_API_BASE=http://localhost:3001
+        - NUXT_PUBLIC_API_BASE=
     container_name: eng-bot-frontend
     expose:
       - "3000"
     environment:
-      - NUXT_PUBLIC_API_BASE=http://localhost:3001
+      - NUXT_PUBLIC_API_BASE=
     depends_on:
       - backend
     restart: unless-stopped