copilot-cli output displays correctly, but copied UTF-8 text becomes mojibake when pasted from WSL or Ubuntu terminal to Windows

### Describe the bug

`copilot-cli` displays Slovak/Czech UTF-8 characters correctly in the terminal, but after copying the output and pasting it back into the prompt or into Windows applications, the text becomes mojibake.

Example displayed correctly:

```text
Môžeme zadať multi-symbol (overenie, že tie enginy naozaj fungujú na 15+ symboloch), alebo rovno run_live.py štruktúru.
``
Môžeme zadať multi-symbol (overenie, že tie enginy naozaj fungujú na 15+ symboloch), alebo rovno run_live.py štruktúru.

### Affected version

1.0.61 and previous

### Steps to reproduce the behavior

Open copilot CLI in WSL / Ubuntu on Windows.
Receive a response containing Slovak/Czech UTF-8 characters.
Verify that the text is displayed correctly in the terminal.
Copy part of the Copilot CLI output from the terminal.
Paste it:

back into the Copilot CLI prompt, or
into a Windows application such as Notepad, Teams, Outlook, VS Code, browser, etc.

Observe that the pasted text contains mojibake instead of valid UTF-8 characters.

### Expected behavior

Copied text should remain valid UTF-8 after paste.

### Additional context

GitHub Copilot CLI 1.0.61.
Run 'copilot update' to check for updates.
LANG=C.UTF-8
LANGUAGE=
LC_CTYPE="C.UTF-8"
LC_NUMERIC="C.UTF-8"
LC_TIME="C.UTF-8"
LC_COLLATE="C.UTF-8"
LC_MONETARY="C.UTF-8"
LC_MESSAGES="C.UTF-8"
LC_PAPER="C.UTF-8"
LC_NAME="C.UTF-8"
LC_ADDRESS="C.UTF-8"
LC_TELEPHONE="C.UTF-8"
LC_MEASUREMENT="C.UTF-8"
LC_IDENTIFICATION="C.UTF-8"
LC_ALL=
C.UTF-8

xterm-256color
/bin/bash

No source file or test is named. Reproduce the copy-and-paste flow in WSL/Ubuntu with the reported C.UTF-8 locale, then trace the CLI's terminal output and clipboard handling; done means Slovak/Czech UTF-8 text remains intact when pasted into the prompt and Windows applications.

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