message: docs(Popover): fix placement demo
diff: <script setup lang="ts">
  import { ref } from 'vue';
  -import VanPopover, { PopoverPlacement } from '..';
  +import VanPopover, { type PopoverPlacement } from '..';
  import VanButton from '../../button';
  import VanField from '../../field';
  import VanPopup from '../../popup';
  -import VanPicker from '../../picker';
  +import VanPicker, {
  + PickerConfirmEventParams,
  + type PickerOption,
  +} from '../../picker';
  import VanGrid from '../../grid';
  import VanGridItem from '../../grid-item';
  import { showToast } from '../../toast';
  @@ -61,7 +64,7 @@ const t = useTranslate({
  },
  });
  -const placements = [
  +const placements: PickerOption[] = [
  'top',
  'top-start',
  'top-end',
  @@ -74,7 +77,7 @@ const placements = [
  'bottom',
  'bottom-start',
  'bottom-end',
  -];
  +].map((item) => ({ text: item, value: item }));
  const show = ref({
  showIcon: false,
  @@ -98,10 +101,10 @@ const onClickChoosePlacement = () => {
  }, 300);
  };
  -const onPickerChange = (value: PopoverPlacement) => {
  +const onPickerChange = (option: PickerConfirmEventParams) => {
  setTimeout(() => {
  show.value.placement = true;
  - currentPlacement.value = value;
  + currentPlacement.value = option.selectedValues[0] as PopoverPlacement;
  });
  };
  