fix(docker): pid 改放 /tmp，规避老内核下 /run 不可写致 nginx 退出

Dockerfile

@@ -19,3 +19,6 @@ RUN npm run build
 FROM nginx:alpine
 COPY --from=build /app/dist /usr/share/nginx/html
 COPY nginx.conf /etc/nginx/conf.d/default.conf
+
+# 老内核(CentOS7)下容器内 /run 不可写，pid 改放 /tmp，避免 master 写 pid 失败而退出
+CMD ["nginx", "-g", "daemon off; pid /tmp/nginx.pid;"]