[Bug]: 输入框很多行内容时，焦点没有跟着输入的地方，焦点自动下移一行

## QwenPaw Version
2.1.0，win10,
输入框很多行内容时，焦点没有跟着输入的地方，焦点自动下移一行。然后打字，它又移到正在输入的行，然后又自动下移一行。

No source file, entry point, or test is identified in the report. First reproduce the multiline-input focus behavior on QwenPaw 2.1.0 under Windows 10, then trace the input component that handles the active line and add or update a focused regression test. Done means the focus remains with the line being edited instead of moving down after each input.

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