升级Vue3，iView替换ElementPlus

- 删除babel配置、更新依赖与入口初始化
- 全量替换UI组件、样式适配，新增迁移文档与标签/过滤器自动化替换脚本

buyer/scripts/fix-duplicate-size.js

@@ -0,0 +1,26 @@
+#!/usr/bin/env node
+const fs = require("fs");
+const path = require("path");
+
+const ROOT = path.join(__dirname, "..", "src");
+
+function walk(dir, files = []) {
+  for (const e of fs.readdirSync(dir, { withFileTypes: true })) {
+    const f = path.join(dir, e.name);
+    if (e.isDirectory()) walk(f, files);
+    else if (e.name.endsWith(".vue")) files.push(f);
+  }
+  return files;
+}
+
+let n = 0;
+for (const file of walk(ROOT)) {
+  let c = fs.readFileSync(file, "utf8");
+  const next = c.replace(/:size="(\d+)"\s+:size="\1"/g, ':size="$1"');
+  if (next !== c) {
+    fs.writeFileSync(file, next);
+    n++;
+    console.log(path.relative(ROOT, file));
+  }
+}
+console.log(`Fixed duplicate :size in ${n} files`);