feat: 新增预算费控模型与报销审批流引擎

后端新增预算费控服务和报销单审批流模块，引入申请人费用画像
算法，优化知识库 RAG 运行时和同步逻辑，完善报销单工作流常
量和明细同步，更新差旅报销规则电子表格，前端新增预算分析
组件和数字员工模型，完善审批对话框和洞察面板交互，优化侧
边栏和顶栏样式，补充单元测试。

web/src/utils/approvalInbox.js

@@ -1,5 +1,6 @@
 import { mapExpenseClaimToRequest } from '../composables/useRequests.js'
 import {
+  canApproveBudgetExpenseApplications,
   canApproveLeaderExpenseClaims,
   isCurrentDirectManagerForRequest,
   isCurrentRequestApplicant,
@@ -17,6 +18,10 @@ export function canProcessApprovalRequest(request, currentUser) {
     return true
   }
 
+  if (node.includes('预算')) {
+    return canApproveBudgetExpenseApplications(currentUser, request)
+  }
+
   const isLeaderApprovalNode = (
     node.includes('直属领导')
     || node.includes('领导审批')