财新无法获取全文

### 路由地址

```routes
/caixin/latest
```

### 完整路由地址

```fullroutes
/caixin/latest?fulltext=true
```

### 相关文档

https://docs.rsshub.app/routes/traditional-media

### 预期是什么？

配置cookie后获得全文

### 实际发生了什么？

并未获得全文

### 部署

自建

### 部署相关信息

_No response_

### 额外信息

```shell
已包含cookie中的以下字段: `SA_USER_UID`, `SA_USER_UNIT`, `SA_USER_DEVICE_TYPE`, `USER_LOGIN_CODE`
```

### 这不是重复的 issue

- [X] 我已经搜索了 [现有 issue](https://github.com/DIYgod/RSSHub/issues)，以确保该错误尚未被报告。

Start at the implementation for the /caixin/latest route and read the linked traditional-media documentation. Reproduce the request with /caixin/latest?fulltext=true and the listed cookie fields, then trace why the response lacks full text. Done means configured cookies allow the route to return the full article content.

Written by the indexing model from the issue text.