* Add unit tests for chat utility functions and enhance statistical data calculation in utils.ts.
* Update utils.ts
---------
Co-authored-by: gru-agent[bot] <185149714+gru-agent[bot]@users.noreply.github.com>
Co-authored-by: Archer <545436317@qq.com>
![gru-agent[bot]'s avatar](/assets/no_avatar-849f9c04a3a0d0cea2424ae97b27447dc64a7dbfae83c036c45b403392f0e8ba.png "gru-agent[bot]"){kind=avatar}