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/services/reimbursements.js

@@ -1,15 +1,32 @@
 import { apiRequest } from './api.js'
 
-export function fetchExpenseClaims() {
-  return apiRequest('/reimbursements/claims')
+function buildListQuery(params = {}) {
+  const search = new URLSearchParams()
+  const page = params.page
+  const pageSize = params.pageSize || params.page_size
+
+  if (page) {
+    search.set('page', String(page))
+  }
+
+  if (pageSize) {
+    search.set('page_size', String(pageSize))
+  }
+
+  const query = search.toString()
+  return query ? `?${query}` : ''
 }
 
-export function fetchApprovalExpenseClaims() {
-  return apiRequest('/reimbursements/claims/approvals')
+export function fetchExpenseClaims(params = {}) {
+  return apiRequest(`/reimbursements/claims${buildListQuery(params)}`)
 }
 
-export function fetchArchivedExpenseClaims() {
-  return apiRequest('/reimbursements/claims/archives')
+export function fetchApprovalExpenseClaims(params = {}) {
+  return apiRequest(`/reimbursements/claims/approvals${buildListQuery(params)}`)
+}
+
+export function fetchArchivedExpenseClaims(params = {}) {
+  return apiRequest(`/reimbursements/claims/archives${buildListQuery(params)}`)
 }
 
 export function fetchExpenseClaimDetail(claimId) {