fix: use expose instead of ports to avoid host port conflicts

docker-compose.yml

@@ -10,8 +10,8 @@ services:
       dockerfile: Dockerfile
     container_name: erp-backend
     restart: unless-stopped
-    ports:
-      - "8000:8000"
+    expose:
+      - "8000"
     environment:
       - DATABASE_URL=postgresql+asyncpg://${POSTGRES_USER}:${POSTGRES_PASSWORD}@postgres:5432/${POSTGRES_DB}
       - REDIS_URL=redis://redis:6379/0
@@ -56,8 +56,8 @@ services:
         - NEXT_PUBLIC_API_URL=${NEXT_PUBLIC_API_URL:-http://localhost:8000/api/v1}
     container_name: erp-frontend
     restart: unless-stopped
-    ports:
-      - "3000:3000"
+    expose:
+      - "3000"
     environment:
       - NEXT_PUBLIC_API_URL=${NEXT_PUBLIC_API_URL:-http://localhost:8000/api/v1}
       - NODE_ENV=production