fix: auto refresh MKH live data

frontend/src/pages/MkhBomData/index.jsx

@@ -33,6 +33,9 @@ const number = (value, digits = 0) => (value === null || value === undefined ||
 const text = (value) => (value === null || value === undefined || value === '' ? '--' : value);
 
 const EMPTY_FILTERS = { keyword: '', scope: 'warning' };
+// 页面长时打开时定期重读。后端共享 10 分钟索引缓存，因此多个页面的轮询
+// 会合并为每个缓存周期一次业务库读取，不会每 2 分钟重复扫远程大表。
+const AUTO_REFRESH_MS = 2 * 60 * 1000;
 
 // 预警等级 → 标签配色
 const WARNING_TONE = {
@@ -277,6 +280,8 @@ const MkhBomData = () => {
   const tableWrapRef = useRef(null);
   const listRequestGateRef = useRef(createRequestGate());
   const detailGenerationRef = useRef(0);
+  const lastListRefreshAtRef = useRef(0);
+  const autoRefreshPendingRef = useRef(false);
   const [bodyHeight, setBodyHeight] = useState(420);
 
   useEffect(() => {
@@ -313,10 +318,10 @@ const MkhBomData = () => {
     return params;
   }, [page, pageSize, sorter, filters]);
 
-  const load = useCallback(async () => {
+  const load = useCallback(async ({ background = false } = {}) => {
     const requestGeneration = listRequestGateRef.current.begin();
-    setLoading(true);
-    setError('');
+    if (!background) setLoading(true);
+    if (!background) setError('');
     try {
       const result = await getMkhBomList({ ...query, live: 1, _refresh: Date.now() });
       if (!listRequestGateRef.current.isCurrent(requestGeneration)) return;
@@ -325,16 +330,38 @@ const MkhBomData = () => {
         return;
       }
       setData(result?.data || { rows: [], total: 0, page: 1, pageSize: 50 });
+      lastListRefreshAtRef.current = Date.now();
+      setError('');
     } catch (requestError) {
       if (!listRequestGateRef.current.isCurrent(requestGeneration)) return;
       setError(requestError?.response?.data?.error || requestError?.message || '加载 MKH-BOM 资料失败');
     } finally {
-      if (listRequestGateRef.current.isCurrent(requestGeneration)) setLoading(false);
+      if (!background && listRequestGateRef.current.isCurrent(requestGeneration)) setLoading(false);
     }
   }, [query]);
 
   useEffect(() => { load(); }, [load]);
 
+  // 页面保持打开时自动更新；从后台切回且数据已超过轮询周期时立即重读。
+  // 后台刷新保留当前表格，不显示全页加载态；请求门仍会阻止旧响应覆盖新数据。
+  useEffect(() => {
+    const refreshIfStale = () => {
+      if (document.visibilityState !== 'visible' || syncing || autoRefreshPendingRef.current) return;
+      if (Date.now() - lastListRefreshAtRef.current < AUTO_REFRESH_MS) return;
+      autoRefreshPendingRef.current = true;
+      load({ background: true }).finally(() => {
+        autoRefreshPendingRef.current = false;
+      });
+    };
+
+    const timer = window.setInterval(refreshIfStale, AUTO_REFRESH_MS);
+    document.addEventListener('visibilitychange', refreshIfStale);
+    return () => {
+      window.clearInterval(timer);
+      document.removeEventListener('visibilitychange', refreshIfStale);
+    };
+  }, [load, syncing]);
+
   const changeFilter = (key) => (value) => {
     setFilters((old) => ({ ...old, [key]: value || '' }));
     setPage(1);