Copilot CLI interactive mode turns blank after submitting a prompt in Windows Terminal, while -p mode works

### Describe the bug

### Summary

In interactive mode, GitHub Copilot CLI renders normally at first, but after I submit a prompt the UI goes blank and no further output is visible.

This happens even with very short prompts that should return only a single sentence.

Non-interactive prompt mode with -p works normally, so the issue appears to be specific to the interactive terminal UI.

### Environment

- GitHub Copilot CLI version: 1.0.71
- OS: Windows
- Terminal: Windows Terminal
- GitHub product version: latest

### Affected version

GitHub Copilot CLI 1.0.71.

### Steps to reproduce the behavior

1. Open Windows Terminal.
2. Start Copilot CLI: copilot
3. Enter any prompt, including a short prompt such as: Reply with one short sentence only.
4. Observe that Thinking appears briefly.
5. The terminal UI then goes blank.

### Expected behavior

After submitting a prompt in interactive mode, Copilot CLI should continue showing Thinking and then render the response in the terminal.

### What actually happened

- Copilot CLI starts and renders normally.
- I enter a prompt.
- It shows Thinking.
- Then the screen turns blank.
- After the blank screen appears, I do not see the response or UI content anymore.

This also happens with very short prompts, including prompts that should only produce a one-sentence response.

### Additional context

I tried the following and still saw the same blank-screen behavior in interactive mode:

- Pressed Ctrl + L
- Pressed ?
- Entered /help
- Tried very short prompts with minimal output
- Tried --screen-reader mode: copilot --screen-reader
--screen-reader mode shows the same issue.

What does work

Non-interactive mode works correctly:

copilot -p "Say hello"

This returns output normally.

Beginne damit, das Problem mit `copilot` in Windows Terminal anhand einer kurzen Eingabeaufforderung zu reproduzieren, und vergleiche anschließend den interaktiven Modus mit `copilot -p "Say hello"` und `copilot --screen-reader`. Der Fix ist vollständig, wenn der interaktive Modus weiterhin Thinking anzeigt und die Antwort rendert, statt leer zu werden, während der nicht interaktive Modus weiterhin funktioniert.

Vom Indexierungsmodell aus dem Issue-Text verfasst.