feat: 增加差旅报销标准测算和财务终审流程

新增差旅报销测算接口及 Spreadsheet 规则解析，审批流程拆分
直属领导审批与财务终审两阶段并细分权限，修复 PDF 文本层
缺失时自动回退 OCR，提交后清理关联会话，前端适配审批流
交互并补充单元测试。

web/src/utils/accessControl.js

@@ -19,8 +19,9 @@ const VIEW_ROLE_RULES = {
   employees: ['manager'],
   settings: ['manager']
 }
-const CLAIM_MANAGER_ROLE_CODES = new Set(['finance', 'executive'])
+const CLAIM_MANAGER_ROLE_CODES = new Set(['executive'])
 const CLAIM_RETURN_ROLE_CODES = new Set(['finance', 'executive', 'manager', 'approver'])
+const CLAIM_LEADER_APPROVAL_ROLE_CODES = new Set(['manager', 'approver'])
 
 function normalizedRoleCodes(user) {
   if (!user) {
@@ -60,6 +61,14 @@ export function canReturnExpenseClaims(user) {
   return normalizedRoleCodes(user).some((roleCode) => CLAIM_RETURN_ROLE_CODES.has(roleCode))
 }
 
+export function canApproveLeaderExpenseClaims(user) {
+  if (Boolean(user?.isAdmin)) {
+    return true
+  }
+
+  return normalizedRoleCodes(user).some((roleCode) => CLAIM_LEADER_APPROVAL_ROLE_CODES.has(roleCode))
+}
+
 export function canAccessAppView(user, viewId) {
   if (!viewId || !user) {
     return false