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>

utils/uploadHelper.js

@@ -0,0 +1,61 @@
+import storage from "@/utils/storage.js";
+import { upload as uploadUrl } from "@/api/common.js";
+
+export function getUploadHeader() {
+  return { accessToken: storage.getAccessToken() };
+}
+
+export function getUploadedUrls(fileList) {
+  return fileList
+    .filter((item) => item.status === "success" && item.url)
+    .map((item) => item.url);
+}
+
+/**
+ * uView Plus u-upload @afterRead handler for lilishop upload API.
+ * Backend returns { result: "fileUrl", ... }.
+ */
+export function handleUploadAfterRead(event, fileList, onSuccess) {
+  const files = [].concat(event.file);
+  files.forEach((file) => {
+    const index = fileList.length;
+    fileList.push({
+      ...file,
+      status: "uploading",
+      message: "上传中",
+    });
+    uni.uploadFile({
+      url: uploadUrl,
+      filePath: file.url,
+      name: "file",
+      header: getUploadHeader(),
+      success: (res) => {
+        try {
+          const data = JSON.parse(res.data);
+          fileList.splice(index, 1, {
+            ...fileList[index],
+            status: "success",
+            message: "",
+            url: data.result,
+          });
+          if (onSuccess) {
+            onSuccess(getUploadedUrls(fileList));
+          }
+        } catch (e) {
+          fileList.splice(index, 1, {
+            ...fileList[index],
+            status: "failed",
+            message: "上传失败",
+          });
+        }
+      },
+      fail: () => {
+        fileList.splice(index, 1, {
+          ...fileList[index],
+          status: "failed",
+          message: "上传失败",
+        });
+      },
+    });
+  });
+}