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/parse_map.js

@@ -0,0 +1,15 @@
+const fs = require('fs');
+const { SourceMapConsumer } = require('source-map');
+(async () => {
+  const mapJson = await (await fetch('http://127.0.0.1:8099/main.dart.js.map')).text().catch(()=>null);
+  if (!mapJson) { console.log('无 sourcemap'); return; }
+  const smc = await new SourceMapConsumer(mapJson);
+  // 解析 299:254 (line:col)
+  const pos = smc.originalPositionFor({ line: 299, column: 254 });
+  console.log('299:254 →', pos.source, pos.line + ':' + pos.column, '|', pos.name);
+  // 也试 299 的前后几行
+  for (const c of [200, 100, 50]) {
+    const p = smc.originalPositionFor({ line: 299, column: c });
+    if (p.source) console.log(`299:${c} →`, p.source.split('/').slice(-2).join('/') + ':' + p.line);
+  }
+})();