feat: 实现供水运营专题大屏BI可视化

- 新增OperationDashboard.vue全屏大屏组件
- 添加6个核心KPI指标卡片: 进水总量/出水总量/产销差率/营收额/平均水质/报警次数
- 实现6个ECharts图表: 供水趋势/水质分布/报警统计/管网空间/设备状态/营收分析
- 创建静态HTML版本operation-dashboard.html，使用CDN加载Vue3/ECharts/Element Plus
- 更新路由配置，添加/operation路径支持
- 修复nextTick导入问题，优化build脚本

🚧 开发者: bot_dev1
📝 任务: #38 [BI] 运营仪表盘 + 供水专题大屏

frontend/node_modules/lodash-es/now.js

@@ -0,0 +1,23 @@
+import root from './_root.js';
+
+/**
+ * Gets the timestamp of the number of milliseconds that have elapsed since
+ * the Unix epoch (1 January 1970 00:00:00 UTC).
+ *
+ * @static
+ * @memberOf _
+ * @since 2.4.0
+ * @category Date
+ * @returns {number} Returns the timestamp.
+ * @example
+ *
+ * _.defer(function(stamp) {
+ *   console.log(_.now() - stamp);
+ * }, _.now());
+ * // => Logs the number of milliseconds it took for the deferred invocation.
+ */
+var now = function() {
+  return root.Date.now();
+};
+
+export default now;