[BUG] The background task preview is not fully displayed in Fullscreen Rendering mode

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

There is a UI rendering issue in Claude Code when Fullscreen Rendering mode is active. The preview of background tasks gets truncated and cannot be viewed completely.

<img width="1543" height="808" alt="Image" src="https://github.com/user-attachments/assets/120d022d-4f30-49bd-95c4-fdd8e7411f4a" />

What Should Happen?

In the standard windowed mode, background task preview (the white output box) render correctly and fully:

<img width="1543" height="808" alt="Image" src="https://github.com/user-attachments/assets/829af0c9-690e-48f7-9634-59ba1b44e998" />

Error Messages/Logs

Steps to Reproduce

1. Enable Fullscreen Rendering refer to the documentation
2. Execute bash commands within Claude Code
3. Press Ctrl + B to switch to the background, then use the keyboard Down key to preview

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.92

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

Obviously, Fullscreen Rendering is the best solution to address flickering and automatic scrolling to the top, and I happily turned it on.