fix: 简化逻辑，确保新建申请时加载默认审批人

- 移除草稿恢复逻辑（从列表页新建时清除所有旧数据）
- 简化 useEffect 为两种情况：
  1. 从选择页面返回：恢复 sessionStorage 数据
  2. 从列表页新建：清除旧数据，加载默认配置

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

frontend/src/pages/business-trip/apply.tsx

@@ -88,20 +88,16 @@ export default function BusinessTripApply() {
 
   // 统一处理：草稿恢复、默认审批人加载、选择页面返回
   const initRef = useRef(false)
-  const fromSelectionRef = useRef(false)
 
   useEffect(() => {
     const fromSelection = location.state?.fromSelection
-    fromSelectionRef.current = !!fromSelection
 
-    console.log('📍 Page init:', { fromSelection, initRef: initRef.current })
-    console.log('🔍 SessionStorage keys:', Object.keys(sessionStorage))
+    console.log('📍 Page init:', { fromSelection, locationState: location.state, initRef: initRef.current })
 
     // 1. 从选择页面返回：恢复所有人员数据
     if (fromSelection) {
       console.log('🔄 Returning from selection page')
       const approversData = sessionStorage.getItem('selectedApprovers')
-      console.log('📦 approvers data:', approversData)
       if (approversData) {
         setApprovers(JSON.parse(approversData))
         console.log('✅ Restored approvers')
@@ -110,7 +106,6 @@ export default function BusinessTripApply() {
       }
 
       const ccData = sessionStorage.getItem('selectedCc')
-      console.log('📦 cc data:', ccData)
       if (ccData) {
         setCcUsers(JSON.parse(ccData))
         console.log('✅ Restored CC')
@@ -127,48 +122,21 @@ export default function BusinessTripApply() {
     }
     initRef.current = true
 
-    // 3. 恢复草稿数据（理由、行程）
-    const draftData = sessionStorage.getItem('businessTripDraft')
-    console.log('📦 draft data exists:', !!draftData)
-
-    if (draftData) {
-      console.log('📦 Restoring draft data')
-      try {
-        const draft = JSON.parse(draftData)
-        if (draft.reason) setReason(draft.reason)
-        if (draft.itineraries && draft.itineraries.length > 0) {
-          const restoredItineraries = draft.itineraries.map((item: any) => ({
-            ...item,
-            startTime: item.startTime ? new Date(item.startTime) : null,
-            endTime: item.endTime ? new Date(item.endTime) : null,
-          }))
-          setItineraries(restoredItineraries)
-        }
-        // 恢复草稿关联的人员数据
-        const approversData = sessionStorage.getItem('selectedApprovers')
-        const ccData = sessionStorage.getItem('selectedCc')
-        console.log('📦 draft approvers:', approversData)
-        console.log('📦 draft cc:', ccData)
-        if (approversData) setApprovers(JSON.parse(approversData))
-        if (ccData) setCcUsers(JSON.parse(ccData))
-      } catch (error) {
-        console.error('❌ Failed to restore draft:', error)
-      }
-      return
-    }
-
-    // 4. 首次进入且无草稿：加载默认审批人和抄送人
-    console.log('🔄 Loading default approvers from backend...')
-    console.log('🔑 Token exists:', !!localStorage.getItem('token'))
+    // 3. 从列表页新建申请：清除旧数据，加载默认配置
+    console.log('🆕 New application - clearing old data and loading defaults')
+    sessionStorage.removeItem('businessTripDraft')
+    sessionStorage.removeItem('selectedApprovers')
+    sessionStorage.removeItem('selectedCc')
+    setReason('')
+    setItineraries([{ startTime: null, endTime: null, departure: '', destination: '', transport: '', tripType: '' as 'oneway' | 'roundtrip' | '', remark: '' }])
+    setApprovers([])
+    setCcUsers([])
 
+    // 4. 加载默认审批人和抄送人
     const loadDefaultApprovers = async () => {
-      // 清除旧数据
-      console.log('🧹 Clearing old selection data')
-      sessionStorage.removeItem('selectedApprovers')
-      sessionStorage.removeItem('selectedCc')
+      console.log('📡 Calling API...')
 
       try {
-        console.log('📡 Calling API...')
         const defaultData = await businessTripApi.getDefaultApprovers()
         console.log('✅ API Response:', defaultData)
 
@@ -176,21 +144,14 @@ export default function BusinessTripApply() {
           console.log('✅ Setting approvers:', defaultData.approvers)
           setApprovers(defaultData.approvers)
           sessionStorage.setItem('selectedApprovers', JSON.stringify(defaultData.approvers))
-        } else {
-          console.log('⚠️ No approvers in response')
         }
         if (defaultData.cc_users && defaultData.cc_users.length > 0) {
           console.log('✅ Setting cc_users:', defaultData.cc_users)
           setCcUsers(defaultData.cc_users)
           sessionStorage.setItem('selectedCc', JSON.stringify(defaultData.cc_users))
-        } else {
-          console.log('⚠️ No cc_users in response')
         }
-
-        console.log('📊 Final state - approvers:', defaultData.approvers?.length, 'cc:', defaultData.cc_users?.length)
       } catch (error: any) {
         console.error('❌ Failed to load default approvers:', error.message)
-        console.error('❌ Error details:', error)
       }
     }