Terminal Input Echoed after Extended Period

### Describe the bug

After leaving the CLI running for an extended period of time, any input including keyboard presses and mouse clicks is echoed back to the output as character codes.

### Affected version

GitHub Copilot CLI 1.0.17

### Steps to reproduce the behavior

1. Leave the CLI running for an extended period of time.
2. Type on the keyboard or click the mouse while the CLI has focus.
3. Observe output in the form of extended character codes.

### Expected behavior

Typing or clicking the mouse does not result in extended character codes appearing in the output.

### Additional context

This has been observed multiple times using the Developer PowerShell window in VS 2022 and VS 2026.

No file or test is named. First reproduce the issue by leaving GitHub Copilot CLI 1.0.17 running in a Developer PowerShell window, then type or click after an extended period and inspect the terminal input and output handling. Done means keyboard and mouse input no longer appears as extended character codes.

索引モデルが issue の本文から書いたものです。