perf(history): reduce export polling load

vehicle-data-platform/apps/web/src/v2/pages/HistoryPage.test.tsx

@@ -41,7 +41,8 @@ function historySeries(vin: string, plate: string, asOf: string): HistorySeriesR
 
 function renderPage() {
   const client = new QueryClient({ defaultOptions: { queries: { retry: false } } });
-  return render(<QueryClientProvider client={client}><MemoryRouter future={ROUTER_FUTURE} initialEntries={['/history?keywords=OLDVIN&dateFrom=2026-07-16T00%3A00&dateTo=2026-07-16T05%3A00']}><HistoryPage /></MemoryRouter></QueryClientProvider>);
+  const view = render(<QueryClientProvider client={client}><MemoryRouter future={ROUTER_FUTURE} initialEntries={['/history?keywords=OLDVIN&dateFrom=2026-07-16T00%3A00&dateTo=2026-07-16T05%3A00']}><HistoryPage /></MemoryRouter></QueryClientProvider>);
+  return { ...view, client };
 }
 
 test('clears stale rows, charts, and evidence as soon as the history scope changes', async () => {
@@ -76,3 +77,17 @@ test('clears stale rows, charts, and evidence as soon as the history scope chang
   expect(await screen.findByText('NEWVIN-evidence')).toBeInTheDocument();
   await waitFor(() => expect(screen.queryByRole('status')).not.toBeInTheDocument());
 });
+
+test('releases export job state immediately after leaving the history page', async () => {
+  mocks.historyMetricCatalog.mockResolvedValue({ categories: [{ key: 'location', label: '位置数据' }], metrics: [metric] });
+  mocks.historyData.mockResolvedValue(historyData('OLDVIN', '旧车牌', 'old-as-of'));
+  mocks.historySeries.mockResolvedValue(historySeries('OLDVIN', '旧车牌', 'old-as-of'));
+  mocks.historyExports.mockResolvedValue([{ id: 'export-running', name: '运行中导出', status: 'running', progress: 30, format: 'csv', category: 'location', keywords: ['OLDVIN'], rowCount: 0, totalRows: 100, processedRows: 30, fileSizeBytes: 0, createdAt: '2026-07-16T04:00:00Z', updatedAt: '2026-07-16T04:00:01Z', evidence: 'test export' }]);
+
+  const { client, unmount } = renderPage();
+  expect(await screen.findByText('运行中导出')).toBeInTheDocument();
+  expect(client.getQueryCache().find({ queryKey: ['history-exports'] })).toBeDefined();
+
+  unmount();
+  await waitFor(() => expect(client.getQueryCache().find({ queryKey: ['history-exports'] })).toBeUndefined());
+});

vehicle-data-platform/apps/web/src/v2/pages/HistoryPage.tsx

@@ -4,7 +4,7 @@ import { FormEvent, useEffect, useMemo, useState } from 'react';
 import { useSearchParams } from 'react-router-dom';
 import { api } from '../../api/client';
 import type { HistoryDataResponse, HistoryDataRow, HistoryExportRequest, HistoryMetricDefinition, HistorySeriesResponse } from '../../api/types';
-import { buildHistorySeriesPanels, formatExportFileSize, formatHistoryValue, formatSeriesGrain, parseHistoryKeywords } from '../domain/history';
+import { buildHistorySeriesPanels, formatExportFileSize, formatHistoryValue, formatSeriesGrain, historyExportPollInterval, parseHistoryKeywords } from '../domain/history';
 import { InlineError } from '../shared/AsyncState';
 import { QUERY_MEMORY, retainPreviousPageWithinScope } from '../queryPolicy';
 
@@ -42,7 +42,13 @@ function CreateExportButton({ request, disabled }: { request: HistoryExportReque
 }
 
 function ExportJobsPanel() {
-  const query = useQuery({ queryKey: ['history-exports'], queryFn: ({ signal }) => api.historyExports(signal), refetchInterval: (current) => current.state.data?.some((job) => job.status === 'queued' || job.status === 'running') ? 1000 : false });
+  const query = useQuery({
+    queryKey: ['history-exports'],
+    queryFn: ({ signal }) => api.historyExports(signal),
+    refetchInterval: (current) => historyExportPollInterval(current.state.data),
+    refetchIntervalInBackground: false,
+    gcTime: QUERY_MEMORY.highVolumeGcTime
+  });
   const jobs = query.data ?? [];
   return <section className="v2-export-jobs"><header><strong>导出任务</strong><span>{jobs.length}</span></header><div>{jobs.slice(0, 6).map((job) => <article key={job.id} title={job.evidence}><i className={`is-${job.status}`} /><div><strong>{job.name}</strong><small>{job.status === 'queued' ? '等待单并发执行' : job.status === 'running' ? `${job.processedRows.toLocaleString('zh-CN')} / ${job.totalRows.toLocaleString('zh-CN')} 行 · ${job.progress}%` : job.status === 'completed' ? `${job.rowCount.toLocaleString('zh-CN')} 行 · ${formatExportFileSize(job.fileSizeBytes)} · 已完成` : job.error || '失败'}</small></div>{job.downloadUrl ? <a href={job.downloadUrl}><IconDownload />下载</a> : <em>{job.status === 'running' ? `${job.progress}%` : '—'}</em>}</article>)}{query.isError ? <div className="v2-history-side-empty">导出任务加载失败</div> : !jobs.length ? <div className="v2-history-side-empty">尚未创建导出任务</div> : null}</div></section>;
 }