feat(platform): summarize vehicle service status

vehicle-data-platform/apps/web/src/test/App.test.tsx

@@ -489,6 +489,14 @@ test('shows selected source scope on vehicle detail', async () => {
               { protocol: 'GB32960', online: false, lastSeen: '2026-07-03 20:11:10', hasRealtime: true, hasHistory: true, hasRaw: true, hasMileage: true },
               { protocol: 'JT808', online: true, lastSeen: '2026-07-03 20:12:10', hasRealtime: true, hasHistory: true, hasRaw: true, hasMileage: true }
             ],
+            serviceStatus: {
+              status: 'degraded',
+              severity: 'warning',
+              title: '部分来源离线',
+              detail: '1/2 个来源在线，车辆服务可用但需要关注离线来源。',
+              sourceCount: 2,
+              onlineSourceCount: 1
+            },
             realtime: [],
             history: { items: [], total: 0, limit: 20, offset: 0 },
             raw: { items: [], total: 0, limit: 10, offset: 0 },
@@ -516,5 +524,7 @@ test('shows selected source scope on vehicle detail', async () => {
 
   expect(await screen.findByText('当前查看范围')).toBeInTheDocument();
   expect(screen.getByText('单一来源：JT808')).toBeInTheDocument();
+  expect(screen.getByText('车辆服务状态')).toBeInTheDocument();
+  expect(screen.getByText('部分来源离线')).toBeInTheDocument();
   expect(fetchMock).toHaveBeenCalledWith(expect.stringContaining('/api/vehicle-service?keyword=VIN001&protocol=JT808'), undefined);
 });