建议提示词模板不要直接发送，允许用户结合模板修改后再发出

比如模板提示词预设了一套“章节概述规范”，有时候我希望ai帮我按照规范总结第5-10章的内容，那我只需要在模板的基础上，再手敲一句“范围：5-10章”再发出就可以。

但是目前的设计是，写好了模板，点击就会直接发送。想达成微调只能点一次模板按钮，中断AI回答，然后再敲一段补充发过去，这样不够灵活。

Start by locating the Dart/Flutter UI for prompt templates and the flow triggered when a template is tapped. Trace how the template is currently sent immediately, then make the resulting prompt editable before sending. Done means a user can add text such as a chapter range and explicitly send the combined prompt.

Escrita pelo modelo de indexação a partir do texto da issue.