Terminal freezes when editing the file name in the "Export Text" Save As dialog

### Windows Terminal version

1.24.11911.0

### Windows build number

10.0.26200.9445

### Other Software

_No response_

### Steps to reproduce

### Windows Terminal version (or build)

Terminal running PowerShell or cmd.exe or Git Bash or Linux (stable Windows Terminal release, Chinese UI locale)

### Steps to reproduce

1. Open Windows Terminal with a eg. PowerShell tab.
2. Right-click the tab and select **Export Text** (导出文本).
3. In the **Save As** dialog that appears (default file name `Desktop.txt`), click into the **File name** field and try to edit it.

### Notes

- UI locale: zh-CN (Windows 11)
- Killing `WindowsTerminal.exe` (and the stuck dialog) is the only way to recover; no crash dialog appears.

### Expected Behavior

The file name should be editable and the export should complete normally when clicking **Save**.

### Actual Behavior

As soon as I try to modify the file name in the Save As dialog, Windows Terminal freezes completely. The dialog and the whole window become unresponsive, and the process has to be killed manually via Task Manager. The freeze is reproducible every time.

### Screenshots

1. Tab context menu with "Export Text" selected:

2. Save As dialog right before the freeze (editing the default file name):

Start by reproducing the Export Text flow in Windows Terminal on Windows 11 with the zh-CN locale, then trace the Save As dialog path used after selecting Export Text. The issue is done when the file name can be edited without freezing and the export completes normally after clicking Save.

Written by the indexing model from the issue text.