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-item.vue

@@ -0,0 +1,86 @@
+<template>
+  <view class="u-time-line-item">
+    <view class="u-time-line-item__node" :style="nodeStyle">
+      <slot name="node">
+        <view class="u-time-line-item__dot" :style="{ backgroundColor: bgColor }"></view>
+      </slot>
+    </view>
+    <view class="u-time-line-item__content">
+      <slot name="content" />
+    </view>
+  </view>
+</template>
+
+<script>
+export default {
+  name: 'UTimeLineItem',
+  props: {
+    nodeTop: {
+      type: [String, Number],
+      default: ''
+    },
+    bgColor: {
+      type: String,
+      default: '#ffffff'
+    }
+  },
+  computed: {
+    nodeStyle() {
+      if (this.nodeTop === '' || this.nodeTop === null || this.nodeTop === undefined) {
+        return {}
+      }
+      const top = typeof this.nodeTop === 'number' ? `${this.nodeTop}rpx` : this.nodeTop
+      return { top }
+    }
+  }
+}
+</script>
+
+<style lang="scss" scoped>
+.u-time-line-item {
+  display: flex;
+  flex-direction: row;
+  position: relative;
+  padding-bottom: 32rpx;
+
+  &:last-child {
+    padding-bottom: 0;
+  }
+
+  &__node {
+    position: relative;
+    width: 32rpx;
+    display: flex;
+    justify-content: center;
+    flex-shrink: 0;
+    z-index: 1;
+  }
+
+  &__dot {
+    width: 16rpx;
+    height: 16rpx;
+    border-radius: 50%;
+    background-color: #ddd;
+  }
+
+  &__content {
+    flex: 1;
+    padding-left: 12rpx;
+  }
+
+  &::before {
+    content: '';
+    position: absolute;
+    left: 15rpx;
+    top: 0;
+    bottom: 0;
+    width: 1px;
+    background-color: #ddd;
+  }
+
+  &:last-child::before {
+    bottom: auto;
+    height: 16rpx;
+  }
+}
+</style>