展示不全的问题

模型回复的消息展示不全，滚动条已经到底了。如果鼠标单击选中往下选可以看到，但是松开鼠标，再点击选中部分的区域，滚动条就会回滚到截图的位置，下面部分回复仍然被遮盖。
The messages displayed by the model are not fully shown; the scroll bar has reached the bottom. If you click and select a portion of the text to scroll down, you can see the remaining content. However, once you release the mouse and click again on the selected area, the scroll bar will return to its previous position, hiding the lower parts of the message again.

Reproduce the problem in the VS Code message view using the attached screenshots as a reference, especially after dragging to the bottom and clicking the selected area. Trace the message display and scrolling entry point; done means the full model response remains visible and the scrollbar does not jump back after selection is released or clicked.

Written by the indexing model from the issue text.