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/isEmpty.js

@@ -0,0 +1,77 @@
+var baseKeys = require('./_baseKeys'),
+    getTag = require('./_getTag'),
+    isArguments = require('./isArguments'),
+    isArray = require('./isArray'),
+    isArrayLike = require('./isArrayLike'),
+    isBuffer = require('./isBuffer'),
+    isPrototype = require('./_isPrototype'),
+    isTypedArray = require('./isTypedArray');
+
+/** `Object#toString` result references. */
+var mapTag = '[object Map]',
+    setTag = '[object Set]';
+
+/** Used for built-in method references. */
+var objectProto = Object.prototype;
+
+/** Used to check objects for own properties. */
+var hasOwnProperty = objectProto.hasOwnProperty;
+
+/**
+ * Checks if `value` is an empty object, collection, map, or set.
+ *
+ * Objects are considered empty if they have no own enumerable string keyed
+ * properties.
+ *
+ * Array-like values such as `arguments` objects, arrays, buffers, strings, or
+ * jQuery-like collections are considered empty if they have a `length` of `0`.
+ * Similarly, maps and sets are considered empty if they have a `size` of `0`.
+ *
+ * @static
+ * @memberOf _
+ * @since 0.1.0
+ * @category Lang
+ * @param {*} value The value to check.
+ * @returns {boolean} Returns `true` if `value` is empty, else `false`.
+ * @example
+ *
+ * _.isEmpty(null);
+ * // => true
+ *
+ * _.isEmpty(true);
+ * // => true
+ *
+ * _.isEmpty(1);
+ * // => true
+ *
+ * _.isEmpty([1, 2, 3]);
+ * // => false
+ *
+ * _.isEmpty({ 'a': 1 });
+ * // => false
+ */
+function isEmpty(value) {
+  if (value == null) {
+    return true;
+  }
+  if (isArrayLike(value) &&
+      (isArray(value) || typeof value == 'string' || typeof value.splice == 'function' ||
+        isBuffer(value) || isTypedArray(value) || isArguments(value))) {
+    return !value.length;
+  }
+  var tag = getTag(value);
+  if (tag == mapTag || tag == setTag) {
+    return !value.size;
+  }
+  if (isPrototype(value)) {
+    return !baseKeys(value).length;
+  }
+  for (var key in value) {
+    if (hasOwnProperty.call(value, key)) {
+      return false;
+    }
+  }
+  return true;
+}
+
+module.exports = isEmpty;