fix(runtime): onGenerateRoute pathElements 越界 RangeError

- buy-service/renew-minioffice 加长度检查 (pathElements.length >= 4/3)
- 根因: Flutter web 深链接渐进式路径解析, onGenerateRoute 被调用多次,
  pathElements 递增 ([,buy-service] -> [,buy-service,1] -> 完整),
  前几次路径短但 pathElements[1]已匹配 -> int.parse([2])/[3] 越界
- 直接访问/刷新 /buy-service/x/y, /renew-minioffice/x 时崩溃
- 恢复 buy_service 实验代码 (data 校验 + mounted 保留)

tools/e2e/diag_routes.js

@@ -0,0 +1,14 @@
+const { chromium } = require('playwright');
+(async () => {
+  const browser = await chromium.launch({ headless: true });
+  for (const route of ['/download', '/contact-stores', '/me', '/orders', '/buy-service/1/ministore']) {
+    const page = await (await browser.newContext({viewport:{width:1280,height:900}})).newPage();
+    let range = 0;
+    page.on('console', m => { if (m.text().includes('RangeError')) range++; });
+    await page.goto('http://127.0.0.1:8099'+route, { waitUntil: 'load' }).catch(()=>{});
+    await page.waitForTimeout(6000);
+    console.log(`${range>0?'✗ '+range+' RangeError':'✓ OK'}  ${route}`);
+    await page.close();
+  }
+  await browser.close();
+})();