Visual artifacts / "ghost" characters remain rendered in TUI after deleting text

### Describe the bug

When backspacing or deleting a text string within the Copilot CLI prompt, the visual interface fails to completely clear or redraw the terminal cells. Characters from the deleted text remain floating/rendered as visual artifacts (ghost characters) even though they are logically removed from the input buffer.

### Affected version

v1.0.65

### Steps to reproduce the behavior

1. Open Copilot CLI in a terminal emulator.

2. Type a long prompt or command string.

3. Use Backspace to rapidly delete or clear portions of the text.

Observe that sporadic characters from the original string remain statically rendered on the screen despite the cursor moving past or behind them.

### Expected behavior

When rapidly deleting character from a long prompt or command string there should not be any remaining "ghost" characters rendered.

### Additional context

_No response_

Reproduza o problema no Copilot CLI v1.0.65 usando um prompt longo e, em seguida, exclua rapidamente o texto com Backspace em um emulador de terminal. Rastreie o caminho de entrada TUI da CLI e o caminho de redesenho das células do terminal, e verifique se a exclusão de texto não deixa caracteres residuais enquanto o cursor se move pelo prompt.

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