refactor: 统一账单列表组件，封装 BillListComponent

- 创建 BillListComponent 组件（基于 v2 风格，紧凑布局）
  - 支持筛选（类型、分类、日期范围）和排序（金额、时间）
  - 支持分页加载、左滑删除、点击详情、多选模式
  - 支持 API 自动加载和 Custom 自定义数据两种模式
- 迁移 6 个页面/组件到新组件：
  - TransactionsRecord.vue
  - EmailRecord.vue
  - ClassificationNLP.vue
  - UnconfirmedClassification.vue
  - BudgetCard.vue
  - ReasonGroupList.vue
- 删除旧版 TransactionList 组件
- 保留 CalendarV2 的特殊版本（有专用功能）
- 添加完整的使用文档和 JSDoc 注释

Web/src/components/ReasonGroupList.vue

@@ -1,4 +1,4 @@
-<template>
+<template>
   <div class="reason-group-list-v2">
     <van-empty
       v-if="groups.length === 0 && !loading"
@@ -78,10 +78,12 @@
         </van-button>
       </template>
 
-      <TransactionList
+      <BillListComponent
+        data-source="custom"
         :transactions="groupTransactions"
         :loading="transactionLoading"
         :finished="transactionFinished"
+        :enable-filter="false"
         @load="loadGroupTransactions"
         @click="handleTransactionClick"
         @delete="handleGroupTransactionDelete"
@@ -185,7 +187,7 @@ import { ref, computed, watch, onBeforeUnmount } from 'vue'
 import { showToast, showSuccessToast, showLoadingToast, closeToast, showConfirmDialog } from 'vant'
 import { getReasonGroups, batchUpdateByReason, getTransactionList } from '@/api/transactionRecord'
 import ClassifySelector from './ClassifySelector.vue'
-import TransactionList from './TransactionList.vue'
+import BillListComponent from './Bill/BillListComponent.vue'
 import TransactionDetail from './TransactionDetail.vue'
 import PopupContainer from './PopupContainer.vue'