fix(runtime): e2e 发现的 3 个 bug 修复

- download: desktop_download_apps SingleChildScrollView 加 primary:true (Scrollbar 缺 ScrollPosition)
- contact-stores: checkDomainAvailability async 后 setState 加 mounted 保护 (dispose 后 setState)
- buy-service: _loadData 加 data 结构校验 + mounted 保护 (API 400 无效参数时 data 为错误结构 -> RangeError)

tools/e2e/node_modules/playwright/jsx-runtime.js

@@ -0,0 +1,42 @@
+/**
+ * Copyright (c) Microsoft Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+function jsx(type, props, key) {
+  return {
+    __pw_type: 'jsx',
+    type,
+    props,
+    key,
+  };
+}
+
+function jsxs(type, props, key) {
+  return {
+    __pw_type: 'jsx',
+    type,
+    props,
+    key,
+  };
+}
+
+// this is used in <></> notation
+const Fragment = { __pw_jsx_fragment: true };
+
+module.exports = {
+  Fragment,
+  jsx,
+  jsxs,
+};