fix: 审批详情页显示出行方式等行程字段

在行程显示中添加以下字段映射：
- departure: 出发地
- transport: 出行方式
- trip_type: 行程类型（oneway→单程, roundtrip→往返）
- remark: 备注
- start_time/end_time: 时间格式改为 YYYY-MM-DD HH:mm

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/pages/approval/detail.tsx

@@ -615,14 +615,27 @@ export default function ApprovalDetail() {
                               {Object.entries(itinerary).map(([ikey, ivalue]) => {
                                 if (ikey === 'id' || ikey === 'estimated_cost') return null
                                 const itineraryLabelMap: Record<string, string> = {
+                                  departure: '出发地',
                                   destination: '目的地',
-                                  start_date: '开始日期',
-                                  end_date: '结束日期',
+                                  start_time: '开始时间',
+                                  end_time: '结束时间',
+                                  transport: '出行方式',
+                                  trip_type: '行程类型',
+                                  remark: '备注',
                                 }
                                 const itineraryLabel = itineraryLabelMap[ikey] || ikey
                                 let displayValue = ivalue as string
-                                if (ikey.includes('date') && ivalue) {
-                                  displayValue = dayjs(String(ivalue)).format('YYYY-MM-DD')
+                                // 处理时间字段
+                                if ((ikey.includes('time') || ikey.includes('date')) && ivalue) {
+                                  displayValue = dayjs(String(ivalue)).format('YYYY-MM-DD HH:mm')
+                                }
+                                // 处理行程类型
+                                if (ikey === 'trip_type' && ivalue) {
+                                  const tripTypeMap: Record<string, string> = {
+                                    oneway: '单程',
+                                    roundtrip: '往返',
+                                  }
+                                  displayValue = tripTypeMap[ivalue as string] || ivalue as string
                                 }
                                 return (
                                   <div key={ikey} className={styles.itineraryRow}>