feat: 重构报销单AI预审流程并添加平台风险规则引擎

- 将AI验审改为AI预审，高风险不再拦截而是随单流转给审批人复核
- 新增平台风险规则评估引擎，支持事由过短、票据异常、重复发票等多种评估器
- 用户上下文增加部门信息(department_name)，认证流程同步关联组织架构
- 规则scenario_json改为中文标签(差旅/费用科目)，统一场景分类
- 新增orchestrator审核流程测试用例
- 前端更新审计视图、差旅报销等相关页面

web/src/composables/useSystemState.js

@@ -90,6 +90,8 @@ function buildAnonymousUser() {
     username: '',
     name: '',
     role: '',
+    department: '',
+    departmentName: '',
     position: '',
     grade: '',
     roleCodes: [],
@@ -107,6 +109,8 @@ function buildLegacyAdminUser(username = '') {
     username: normalized,
     name,
     role: DEFAULT_USER_ROLE,
+    department: '',
+    departmentName: '',
     position: DEFAULT_USER_ROLE,
     grade: '',
     roleCodes: ['manager'],
@@ -135,6 +139,8 @@ function readStoredUser() {
           username,
           name,
           role: String(payload.role || DEFAULT_USER_ROLE),
+          department: String(payload.department || payload.departmentName || ''),
+          departmentName: String(payload.departmentName || payload.department || ''),
           position: String(payload.position || ''),
           grade: String(payload.grade || ''),
           roleCodes,