fix: 简化 useEffect 逻辑，确保默认审批人正确加载

- 移除嵌套的异步函数，直接在 useEffect 中处理
- 只依赖 location.state?.fromSelection，避免不必要的重新执行
- 优化初始化流程：选择页面返回 > 草稿恢复 > 默认数据加载

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

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

@@ -88,43 +88,43 @@ 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)
-  useEffect(() => {
-    // 防止重复执行
-    if (initRef.current) {
-      // 只有从选择页面返回时才重新执行
-      if (!location.state?.fromSelection) {
-        return
-      }
-    }
+  const fromSelectionRef = useRef(false)
 
+  useEffect(() => {
     const fromSelection = location.state?.fromSelection
-    console.log('📍 Page init:', { fromSelection, path: location.pathname })
+    fromSelectionRef.current = !!fromSelection
+
+    console.log('📍 Page init:', { fromSelection, 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')
       if (approversData) {
-        const approvers = JSON.parse(approversData) as ApproverItem[]
-        setApprovers(approvers)
-        console.log('✅ Restored approvers:', approvers)
+        setApprovers(JSON.parse(approversData))
+        console.log('✅ Restored approvers')
       } else {
         setApprovers([])
       }
 
       const ccData = sessionStorage.getItem('selectedCc')
       if (ccData) {
-        const cc = JSON.parse(ccData) as ApproverItem[]
-        setCcUsers(cc)
-        console.log('✅ Restored CC:', cc)
+        setCcUsers(JSON.parse(ccData))
+        console.log('✅ Restored CC')
       } else {
         setCcUsers([])
       }
-      initRef.current = true
       return
     }
 
-    // 2. 恢复草稿数据（理由、行程）
+    // 2. 非首次进入且已初始化过：跳过
+    if (initRef.current) {
+      console.log('⏭️ Already initialized, skipping')
+      return
+    }
+    initRef.current = true
+
+    // 3. 恢复草稿数据（理由、行程）
     const draftData = sessionStorage.getItem('businessTripDraft')
     if (draftData) {
       console.log('📦 Restoring draft data')
@@ -139,29 +139,21 @@ export default function BusinessTripApply() {
           }))
           setItineraries(restoredItineraries)
         }
-      } catch (error) {
-        console.error('❌ Failed to restore draft:', error)
-      }
-    }
-
-    // 3. 加载默认审批人和抄送人（仅在首次且无草稿时）
-    const loadDefaultApprovers = async () => {
-      if (initRef.current) return
-      initRef.current = true
-
-      // 如果有草稿数据，不加载默认值
-      if (draftData) {
-        console.log('⏭️ Skipping default load (has draft)')
         // 恢复草稿关联的人员数据
         const approversData = sessionStorage.getItem('selectedApprovers')
         const ccData = sessionStorage.getItem('selectedCc')
         if (approversData) setApprovers(JSON.parse(approversData))
         if (ccData) setCcUsers(JSON.parse(ccData))
-        return
+      } catch (error) {
+        console.error('❌ Failed to restore draft:', error)
       }
+      return
+    }
 
-      // 清除旧数据，加载默认配置
-      console.log('🔄 Loading default approvers from backend...')
+    // 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...')
+    const loadDefaultApprovers = async () => {
+      // 清除旧数据
       sessionStorage.removeItem('selectedApprovers')
       sessionStorage.removeItem('selectedCc')
 
@@ -183,7 +175,7 @@ export default function BusinessTripApply() {
     }
 
     loadDefaultApprovers()
-  }, [location.state])
+  }, [location.state?.fromSelection])
 
   // 计算总时长（累加所有行程的天数）
   const totalDuration = useMemo(() => {