feat: 接入法制日报机构并新增 15 应用 Playwright 回归测试

- 新增法制日报机构种子数据（机构/用户/分类/15应用/知识库），登录页默认账号预填
- 引入 Playwright e2e：登录复用 storageState，覆盖对话/补全/工作流/智能体四类交互
- 配置测试脚本与产物 gitignore

Co-authored-by: Cursor <cursor@cursor.com>

apps/web/src/app/(auth)/login/page.tsx

@@ -20,7 +20,7 @@ import {
 } from "lucide-react";
 
 export default function LoginPage() {
-  const [email, setEmail] = useState("kj-admin@govai.gov.cn");
+  const [email, setEmail] = useState("fazhiribao@govai.gov.cn");
   const [password, setPassword] = useState("admin123");
   const [loading, setLoading] = useState(false);
   const [errorMsg, setErrorMsg] = useState("");