[Feature]: 历史对话的自动生成的标题需要表意更清晰

## Summary

主界面左侧的历史对话的自动生成的标题需要加强，现在太没参考价值了。
这是qwenpaw自动生成的：

这是hermes自动生成的：

这是workbuddy自动生成的：

## Proposed Solution

自动生成的标题需要表意更清晰

## Additional Context

Windows11 desktop，2.1beta1

Start by locating the history-sidebar title-generation entry point and reviewing the three attached examples alongside the current behavior. Clarify measurable criteria for a more meaningful title, then verify the result in the Windows 11 desktop build; the issue provides no file or test path.

Scritto dal modello di indicizzazione a partire dal testo della issue.