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/asynckit/lib/async.js

@@ -0,0 +1,34 @@
+var defer = require('./defer.js');
+
+// API
+module.exports = async;
+
+/**
+ * Runs provided callback asynchronously
+ * even if callback itself is not
+ *
+ * @param   {function} callback - callback to invoke
+ * @returns {function} - augmented callback
+ */
+function async(callback)
+{
+  var isAsync = false;
+
+  // check if async happened
+  defer(function() { isAsync = true; });
+
+  return function async_callback(err, result)
+  {
+    if (isAsync)
+    {
+      callback(err, result);
+    }
+    else
+    {
+      defer(function nextTick_callback()
+      {
+        callback(err, result);
+      });
+    }
+  };
+}