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>

manifest.json

@@ -1,4 +1,5 @@
 {
+    "vueVersion" : "3",
     "name" : "lilishop",
     "appid" : "__UNI__ED807EA",
     "description" : "",
@@ -204,9 +205,6 @@
         "permission" : {
             "scope.userLocation" : {
                 "desc" : "位置信息将用于高德地图的效果展示"
-            },
-            "scope.writePhotosAlbum" : {
-                "desc" : "将用于保存图片"
             }
         },
         "plugins" : {},