deploy: allow services to reach host infrastructure

deploy/docker-compose.yml

@@ -3,6 +3,9 @@ name: firstleg-${DEPLOY_ENV:-test}
 x-common: &common
   restart: unless-stopped
   networks: [firstleg-network, infra-network]
+  # 测试机复用宿主机的 MySQL、Redis、Nacos 时，容器通过此别名访问宿主机。
+  extra_hosts:
+    - "host.docker.internal:host-gateway"
   environment: &common-environment
     SPRING_PROFILES_ACTIVE: ${SPRING_PROFILES_ACTIVE:-cn}
     NACOS_SERVER_ADDR: ${NACOS_SERVER_ADDR}