[Feature Request]: 让reference里的text unit也能直接通过web访问

[RedwindA]

Do you need to file an issue?

• I have searched the existing issues and this feature is not already filed.
• My model is hosted on OpenAI or Azure. If not, please look at the "model providers" issue and don't file a new one here.
• I believe this is a legitimate feature request, not just a question. If this is a question, please use the Discussions area.

Is your feature request related to a problem? Please describe.

如题，目前仍然只能看到LLM生成的内容这一层级，web还是看不到原文，如果web能访问对应的text unit，溯源原文的时候就不用手动打开parquet文件

Describe the solution you'd like

No response

Additional context

No response

[KylinMountain]

但其实有时候输出的source 就是text unit，只是部分会输出 仍然看不到整个输入文档，可能也不太现实，毕竟可能整个文档很大。