refactor: 移动端升级 Vue3 + uView Plus

将 lilishop-uniapp 从 Vue2/uView 1.6 迁移到 Vue3/uview-plus，优先支持 H5/微商城与微信小程序；移除 vendored uview-ui，改用 npm 依赖、Vuex4 与迁移脚本/补丁，并补充 VUE3_MIGRATION.md 回归清单。

Co-authored-by: Cursor <cursoragent@cursor.com>

pages/promotion/point/pointList.vue

@@ -20,12 +20,12 @@
             <view class="index-item" v-for="(item, key) in nav.goods" :key="key" @click="toGoods(item)">
               <view class="index-item-img">
                 <u-image :src="item.thumbnail" mode="aspectFit">
-                  <u-loading slot="loading"></u-loading>
+                  <template #loading><u-loading></u-loading></template>
                 </u-image>
                 <view class="index-item-title">{{ item.goodsName }}</view>
                 <view class="index-item-price flex flex-a-c flex-j-sb">
                   <div class="point"><span>{{ item.points }}</span>积分</div> 
-                  <span class="tipsMkt">¥{{ item.originalPrice | unitPrice }}</span>
+                  <span class="tipsMkt">¥{{unitPrice(item.originalPrice) }}</span>
                 </view>
               </view>
             </view>