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>

plugins/APPUpdate/index.js

@@ -918,3 +918,12 @@ export default function (isPrompt = false) {
   });
 }
 // #endif
+
+// #ifndef APP-PLUS
+export default function APPUpdate() {}
+export const getCurrentNo = function (callback) {
+  callback && callback({ versionCode: "", version: "" });
+};
+export const getServerNo = function () {};
+export const getDownload = function () {};
+// #endif