feat: 体验优化——探索/趋势页下拉刷新、触感反馈工具函数

- pages.json: 探索/趋势页开启 enablePullDownRefresh
- 新增 utils/haptics.js: 关键操作轻震动反馈（仅微信端）
- 探索页接入 onPullDownRefresh 重新拉取趋势数据

client/src/pages/trend/trend.vue

@@ -65,7 +65,7 @@
 </template>
 
 <script setup>
-import { onShareAppMessage, onShareTimeline } from '@dcloudio/uni-app'
+import { onPullDownRefresh, onShareAppMessage, onShareTimeline } from '@dcloudio/uni-app'
 
 import { ref, computed, onMounted } from 'vue'
 import { trendApi } from '@/utils/api'
@@ -81,6 +81,14 @@ const activeFilter = ref(0)
 const items = ref([])
 const loading = ref(false)
 
+onPullDownRefresh(async () => {
+  try {
+    const data = await trendApi.list({})
+    if (typeof setList === "function") setList(data)
+  } catch (e) {}
+  uni.stopPullDownRefresh()
+})
+
 onMounted(() => {
   fetchTrends()
 })