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/_mapCacheDelete.js

@@ -0,0 +1,18 @@
+var getMapData = require('./_getMapData');
+
+/**
+ * Removes `key` and its value from the map.
+ *
+ * @private
+ * @name delete
+ * @memberOf MapCache
+ * @param {string} key The key of the value to remove.
+ * @returns {boolean} Returns `true` if the entry was removed, else `false`.
+ */
+function mapCacheDelete(key) {
+  var result = getMapData(this, key)['delete'](key);
+  this.size -= result ? 1 : 0;
+  return result;
+}
+
+module.exports = mapCacheDelete;