fix: 修复设备管理页面前后端分页混合导致的数据闪烁问题

- 移除 append/loadMore 模式，改为纯后端分页
- 删除前端 slice useEffect，翻页时只调用后端请求
- 清理 loadMoreRef/hasMoreRef/deviceLoadingMore 等无用变量
- 删除 currentPageDevices state，allDevices 即当前页数据

frontend/src/pages/DeviceManagement.jsx

@@ -118,7 +118,6 @@ function DeviceManagement() {
   const [batchStatusLoading, setBatchStatusLoading] = useState(false);
 
   const [exportModalVisible, setExportModalVisible] = useState(false);
-  const [currentPageDevices, setCurrentPageDevices] = useState([]);
 
   const [selectedDevices, setSelectedDevices] = useState([]);
   const [selectAll, setSelectAll] = useState(false);
@@ -127,19 +126,10 @@ function DeviceManagement() {
 
   const debouncedKeyword = useDebounce(keyword, DEBOUNCE_DELAY);
 
-  const loadMoreRef = useRef(null);
-  const hasMoreRef = useRef(true);
-  const isLoadingRef = useRef(false);
-  const [deviceLoadingMore, setDeviceLoadingMore] = useState(false);
-
   const fetchDevices = useCallback(
-    async (page = 1, pageSize = 50, append = false) => {
+    async (page = 1, pageSize = 50) => {
       try {
-        if (append) {
-          setDeviceLoadingMore(true);
-        } else {
-          setLoading(true);
-        }
+        setLoading(true);
 
         const params = {
           page,
@@ -155,20 +145,13 @@ function DeviceManagement() {
         const { devices: deviceList, total } = response.data;
 
         const processedDevices = deviceList.map(processDeviceData);
-
-        if (append) {
-          setAllDevices(prev => [...prev, ...processedDevices]);
-        } else {
-          setAllDevices(processedDevices);
-        }
+        setAllDevices(processedDevices);
         setPagination(prev => ({ ...prev, current: page, pageSize, total }));
-        hasMoreRef.current = page * pageSize < total;
       } catch (error) {
         message.error('获取设备列表失败');
         console.error('获取设备列表失败:', error);
       } finally {
         setLoading(false);
-        setDeviceLoadingMore(false);
       }
     },
     [debouncedKeyword, status, type, roomId, rackId]
@@ -260,72 +243,6 @@ function DeviceManagement() {
     }
   }, [searchParams, setSearchParams]);
 
-  useEffect(() => {
-    if (allDevices.length > 0) {
-      const start = (pagination.current - 1) * pagination.pageSize;
-      const end = start + pagination.pageSize;
-      const currentPageData = allDevices.slice(start, end);
-      setCurrentPageDevices(currentPageData);
-    } else {
-      setCurrentPageDevices([]);
-    }
-  }, [allDevices, pagination.current, pagination.pageSize]);
-
-  const handleLoadMoreDevices = useCallback(() => {
-    if (!hasMoreRef.current || isLoadingRef.current || deviceLoadingMore) return;
-    if (
-      debouncedKeyword ||
-      status !== 'all' ||
-      type !== 'all' ||
-      roomId !== 'all' ||
-      rackId !== 'all'
-    ) {
-      return;
-    }
-    isLoadingRef.current = true;
-    const nextPage = pagination.current + 1;
-    fetchDevices(nextPage, pagination.pageSize, true).then(() => {
-      isLoadingRef.current = false;
-    });
-  }, [
-    pagination.current,
-    pagination.pageSize,
-    debouncedKeyword,
-    status,
-    type,
-    roomId,
-    rackId,
-    deviceLoadingMore,
-    fetchDevices,
-  ]);
-
-  useEffect(() => {
-    if (!loadMoreRef.current) return;
-
-    const observer = new IntersectionObserver(
-      entries => {
-        if (entries[0].isIntersecting && hasMoreRef.current && !deviceLoadingMore) {
-          if (
-            !debouncedKeyword &&
-            status === 'all' &&
-            type === 'all' &&
-            roomId === 'all' &&
-            rackId === 'all'
-          ) {
-            handleLoadMoreDevices();
-          }
-        }
-      },
-      { threshold: 0.1, rootMargin: '100px' }
-    );
-
-    observer.observe(loadMoreRef.current);
-
-    return () => {
-      observer.disconnect();
-    };
-  }, [handleLoadMoreDevices, deviceLoadingMore, debouncedKeyword, status, type, roomId, rackId]);
-
   const showModal = (device = null) => {
     setEditingDevice(device);
     setModalVisible(true);
@@ -347,7 +264,7 @@ function DeviceManagement() {
       }
 
       setModalVisible(false);
-      fetchDevices(1, pagination.pageSize, false);
+      fetchDevices(1, pagination.pageSize);
       setEditingDevice(null);
     } catch (error) {
       const errorMsg = error.response?.data?.error || error.message || '未知错误';
@@ -385,13 +302,7 @@ function DeviceManagement() {
 
   const handleTableChange = newPagination => {
     setPagination(newPagination);
-
-    const start = (newPagination.current - 1) * newPagination.pageSize;
-    const end = start + newPagination.pageSize;
-    const currentPageData = allDevices.slice(start, end);
-    setCurrentPageDevices(currentPageData);
-
-    fetchDevices(newPagination.current, newPagination.pageSize, false);
+    fetchDevices(newPagination.current, newPagination.pageSize);
   };
 
   const handleBatchDelete = async () => {
@@ -409,7 +320,7 @@ function DeviceManagement() {
           message.success(response.data.message || '批量删除成功');
           setSelectedDevices([]);
           setSelectAll(false);
-          fetchDevices(1, 50, false);
+          fetchDevices(1, 50);
         } catch (error) {
           message.error('批量删除失败');
           console.error('批量删除设备失败:', error);
@@ -436,7 +347,7 @@ function DeviceManagement() {
           message.success(response.data.message || '成功删除所有设备');
           setSelectedDevices([]);
           setSelectAll(false);
-          fetchDevices(1, 50, false);
+          fetchDevices(1, 50);
         } catch (error) {
           message.error('删除所有设备失败');
           console.error('删除所有设备失败:', error);
@@ -464,7 +375,7 @@ function DeviceManagement() {
           message.success(response.data.message || '设备已标记为空闲');
           setSelectedDevices([]);
           setSelectAll(false);
-          fetchDevices(1, 50, false);
+          fetchDevices(1, 50);
         } catch (error) {
           message.error(error.response?.data?.error || '标记为空闲失败');
           console.error('标记为空闲失败:', error);
@@ -484,7 +395,7 @@ function DeviceManagement() {
         try {
           await axios.delete(`/api/devices/${deviceId}`);
           message.success('设备删除成功');
-          fetchDevices(1, pagination.pageSize, false);
+          fetchDevices(1, pagination.pageSize);
         } catch (error) {
           message.error('设备删除失败');
           console.error('设备删除失败:', error);
@@ -530,7 +441,7 @@ function DeviceManagement() {
       setBatchStatusModalVisible(false);
       setSelectedDevices([]);
       setSelectAll(false);
-      fetchDevices(1, pagination.pageSize, false);
+      fetchDevices(1, pagination.pageSize);
     } catch (error) {
       message.error('批量状态变更失败');
       console.error('批量状态变更失败:', error);
@@ -552,7 +463,7 @@ function DeviceManagement() {
     if (scope === 'selected') {
       deviceIds = selectedDevices;
     } else if (scope === 'currentPage') {
-      deviceIds = currentPageDevices.map(device => device.deviceId);
+      deviceIds = allDevices.map(device => device.deviceId);
     } else if (scope === 'all') {
       deviceIds = allDevices.map(device => device.deviceId);
     }
@@ -621,7 +532,7 @@ function DeviceManagement() {
       }
 
       setTimeout(() => {
-        fetchDevices(1, pagination.pageSize, false);
+        fetchDevices(1, pagination.pageSize);
       }, 1000);
     } catch (error) {
       let errorMessage = '导入失败';
@@ -1153,7 +1064,7 @@ function DeviceManagement() {
               </Space>
               <Button
                 icon={<ReloadOutlined />}
-                onClick={() => fetchDevices(1, pagination.pageSize, false)}
+                onClick={() => fetchDevices(1, pagination.pageSize)}
                 style={{
                   borderRadius: designTokens.borderRadius.medium,
                   border: `1px solid ${designTokens.colors.border.light}`,
@@ -1345,21 +1256,6 @@ function DeviceManagement() {
                 return index % 2 === 0 ? 'ant-table-row-even' : 'ant-table-row-odd';
               }}
             />
-            {hasMoreRef.current &&
-              !debouncedKeyword &&
-              status === 'all' &&
-              type === 'all' &&
-              roomId === 'all' &&
-              rackId === 'all' && (
-                <div ref={loadMoreRef} style={{ textAlign: 'center', padding: '20px' }}>
-                  {deviceLoadingMore && <Spin tip="加载更多设备..." />}
-                </div>
-              )}
-            {!hasMoreRef.current && allDevices.length > 0 && (
-              <div style={{ textAlign: 'center', padding: '16px', color: '#999' }}>
-                已加载全部 {pagination.total} 个设备
-              </div>
-            )}
           </div>
         )}
       </Card>
@@ -1397,7 +1293,7 @@ function DeviceManagement() {
       <ExportModal
         visible={exportModalVisible}
         selectedDevices={selectedDevices}
-        currentPageDevices={currentPageDevices}
+        currentPageDevices={allDevices}
         allDevices={allDevices}
         onExport={handleEnhancedExport}
         onCancel={() => setExportModalVisible(false)}