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/run.js

@@ -0,0 +1,88 @@
+// e2e 测试：遍历公开路由，捕获 Flutter 错误（print→console 的 CK_ERROR/CK_STACK）
+const { chromium } = require('playwright');
+const BASE = 'http://127.0.0.1:8099';
+
+// 公开路由（不需登录）。动态参数用合理默认值
+const ROUTES = [
+  '/',
+  '/shop',
+  '/shop/310',
+  '/about-us',
+  '/contact-us',
+  '/contact-stores',
+  '/download',
+  '/blog/310',
+  '/view-blog/52',
+  '/igoshow-learn-more',
+  '/minipos-learn-more',
+  '/buy-service/1/pos',
+  '/forgot-password',
+  '/new-user',
+  '/privacy-policy',
+  '/return-policy',
+  '/service-policy',
+  '/end-user-license-agreement',
+];
+
+const results = [];
+
+async function testRoute(browser, route) {
+  const ctx = await browser.newContext({ viewport: { width: 1280, height: 900 } });
+  const page = await ctx.newPage();
+  const errors = [];
+  const ckStacks = [];
+
+  page.on('pageerror', e => errors.push(`PAGEERROR: ${e.message.slice(0, 200)}`));
+  page.on('console', m => {
+    const t = m.text();
+    if (t.startsWith('CK_ERROR:')) errors.push(t);
+    if (t.startsWith('CK_STACK:')) {
+      // 提取项目文件:行号
+      const proj = t.match(/flutter_wisetronic\/[^\s]+:\d+/g);
+      if (proj) ckStacks.push([...new Set(proj)].slice(0, 3));
+    }
+  });
+
+  try {
+    await page.goto(BASE + route, { waitUntil: 'load', timeout: 30000 });
+    await page.waitForTimeout(5000); // 等 Flutter 渲染 + API
+  } catch (e) {
+    errors.push(`GOTO_ERR: ${e.message.slice(0, 100)}`);
+  }
+
+  const status = errors.length === 0 ? '✓ OK' : `✗ ${errors.length} 错误`;
+  console.log(`${status.padEnd(12)} ${route}`);
+  if (errors.length > 0) {
+    console.log('             错误: ' + errors.slice(0, 3).join(' | ').slice(0, 250));
+    if (ckStacks.length > 0) console.log('             位置: ' + JSON.stringify(ckStacks[0]));
+  }
+  results.push({ route, errors, ckStacks });
+  await ctx.close();
+}
+
+(async () => {
+  console.log(`Flutter e2e 测试：${ROUTES.length} 个公开路由\n`);
+  const browser = await chromium.launch({ headless: true });
+  for (const r of ROUTES) {
+    await testRoute(browser, r);
+  }
+  await browser.close();
+
+  // 汇总
+  const failed = results.filter(r => r.errors.length > 0);
+  console.log(`\n========== 汇总 ==========`);
+  console.log(`总计 ${results.length} 路由，${failed.length} 个有错误`);
+  if (failed.length > 0) {
+    console.log('\n失败路由 + 崩溃位置:');
+    const locMap = {};
+    for (const f of failed) {
+      const loc = f.ckStacks[0] ? f.ckStacks[0][0] : '(无堆栈)';
+      locMap[loc] = locMap[loc] || [];
+      locMap[loc].push(f.route);
+    }
+    for (const [loc, routes] of Object.entries(locMap)) {
+      console.log(`  ${loc}`);
+      console.log(`    影响: ${routes.join(', ')}`);
+    }
+  }
+})();