feat: 统一后端分页查询与前端服务层适配

后端新增通用分页模块，为报销单、员工、预算、agent 资产等
端点统一接入分页参数和游标查询，优化 repository 层分页实
现，前端服务层适配分页响应结构，完善预算图表和全局样式，
优化侧边栏和企业选择器组件，引入 Element Plus 插件注册。

web/src/views/scripts/ArchiveCenterView.js

@@ -1,4 +1,5 @@
 import { computed, ref } from 'vue'
+import { ElDropdown, ElDropdownItem, ElDropdownMenu } from 'element-plus/es/components/dropdown/index.mjs'
 
 import EnterpriseListPage from '../../components/shared/EnterpriseListPage.vue'
 import { mapExpenseClaimToRequest } from '../../composables/useRequests.js'
@@ -91,6 +92,9 @@ function resolveFilterLabel(options, activeValue, fallbackLabel) {
 export default {
   name: 'ArchiveCenterView',
   components: {
+    ElDropdown,
+    ElDropdownItem,
+    ElDropdownMenu,
     EnterpriseListPage,
     TravelRequestDetailView
   },

web/src/views/scripts/BudgetCenterView.js

@@ -1,5 +1,8 @@
 import { computed, onMounted, ref, watch } from 'vue'
-import { ElButton, ElInput, ElPagination, ElTable, ElTableColumn } from 'element-plus'
+import { ElButton } from 'element-plus/es/components/button/index.mjs'
+import { ElInput } from 'element-plus/es/components/input/index.mjs'
+import { ElPagination } from 'element-plus/es/components/pagination/index.mjs'
+import { ElTable, ElTableColumn } from 'element-plus/es/components/table/index.mjs'
 
 import BudgetTrendChart from '../../components/charts/BudgetTrendChart.vue'
 import EnterpriseSelect from '../../components/shared/EnterpriseSelect.vue'

web/src/views/scripts/TravelReimbursementCreateView.js

@@ -1,5 +1,6 @@
 import { computed, nextTick, onBeforeUnmount, onMounted, ref, watch } from 'vue'
 import { useRouter } from 'vue-router'
+import { ElDialog } from 'element-plus/es/components/dialog/index.mjs'
 
 import ConfirmDialog from '../../components/shared/ConfirmDialog.vue'
 import TravelReimbursementInsightPanel from '../../components/travel/TravelReimbursementInsightPanel.vue'
@@ -507,6 +508,7 @@ function buildReviewMainMessageText(message) {
 export default {
   name: 'TravelReimbursementCreateView',
   components: {
+    ElDialog,
     ConfirmDialog,
     TravelReimbursementInsightPanel,
     TravelReimbursementMessageItem