perf(web): warm frequent routes during idle time

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

@@ -75,7 +75,17 @@ function eventTone(type: string) {
 function VehiclePicker({ value, onChange, onSelect }: { value: string; onChange: (value: string) => void; onSelect: (vehicle: VehicleRow) => void }) {
   const [open, setOpen] = useState(false);
   const [debounced, setDebounced] = useState(value.trim());
+  const closeTimerRef = useRef<number>();
   useEffect(() => { const timer = window.setTimeout(() => setDebounced(value.trim()), 220); return () => window.clearTimeout(timer); }, [value]);
+  useEffect(() => () => window.clearTimeout(closeTimerRef.current), []);
+  const openPicker = () => {
+    window.clearTimeout(closeTimerRef.current);
+    setOpen(true);
+  };
+  const closePicker = () => {
+    window.clearTimeout(closeTimerRef.current);
+    closeTimerRef.current = window.setTimeout(() => setOpen(false), 140);
+  };
   const params = useMemo(() => {
     const next = new URLSearchParams({ limit: '10', offset: '0' });
     if (debounced) next.set('keyword', debounced);
@@ -87,7 +97,7 @@ function VehiclePicker({ value, onChange, onSelect }: { value: string; onChange:
     <IconSearch />
     <input
       aria-label="搜索轨迹车辆" autoComplete="off" placeholder="输入车牌 / VIN / 终端标识"
-      value={value} onFocus={() => setOpen(true)} onBlur={() => window.setTimeout(() => setOpen(false), 140)}
+      value={value} onFocus={openPicker} onBlur={closePicker}
       onChange={(event) => { onChange(event.target.value); setOpen(true); }}
     />
     {value ? <button type="button" aria-label="清空车辆" onMouseDown={(event) => event.preventDefault()} onClick={() => onChange('')}><IconClose /></button> : null}