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/grapheme-splitter/index.d.ts

@@ -0,0 +1,24 @@
+// Type definitions for grapheme-splitter
+
+/*~ Note that ES6 modules cannot directly export class objects.
+ *~ This file should be imported using the CommonJS-style:
+ *~
+ *~   import GraphemeSplitter = require('grapheme-splitter')
+ *~
+ *~ Refer to the documentation to understand common
+ *~ workarounds for this limitation of ES6 modules.
+ *~
+ *~   https://www.typescriptlang.org/docs/handbook/declaration-files/introduction.html
+ */
+
+declare class GraphemeSplitter {
+  constructor();
+  /** iterate the string to an iterable iterator of grapheme clusters */
+  iterateGraphemes(s: string): IterableIterator<string>;
+  /** split the string to an array of grapheme clusters */
+  splitGraphemes(s: string): string[];
+  /** count the number of grapheme clusters in a string */
+  countGraphemes(s: string): number;
+}
+
+export = GraphemeSplitter;