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>

components/u-time-line/u-time-line.vue

@@ -0,0 +1,18 @@
+<template>
+  <view class="u-time-line">
+    <slot />
+  </view>
+</template>
+
+<script>
+export default {
+  name: 'UTimeLine'
+}
+</script>
+
+<style lang="scss" scoped>
+.u-time-line {
+  display: flex;
+  flex-direction: column;
+}
+</style>