feat: 完善差旅票据行程提取与费用明细回填逻辑

增强文档智能识别的票据场景关键词和字段提取能力，优化
会话关联草稿报销单的解析路径，修复费用明细合并和票据
去重边界问题，前端改进报销创建和审批详情交互，补充单
元测试覆盖。

web/tests/requestProgressSteps.test.mjs

@@ -119,7 +119,7 @@ test('travel expense items describe departure return and lodging time below the
       {
         id: 'outbound-train',
         item_type: 'train_ticket',
-        item_reason: '从广州南到北京南',
+        item_reason: '广州南-北京南',
         item_location: '北京',
         item_date: '2026-05-13',
         item_amount: 354,
@@ -137,7 +137,7 @@ test('travel expense items describe departure return and lodging time below the
       {
         id: 'return-train',
         item_type: 'train_ticket',
-        item_reason: '从北京南到广州南',
+        item_reason: '北京南-广州南',
         item_location: '广州',
         item_date: '2026-05-15',
         item_amount: 354,