pi-coding-agent `/copy` command garbles Chinese characters on Windows

[googao]

What happened?

When using the built-in /copy command to copy text containing Chinese characters to the clipboard on Windows, the pasted content shows garbled/corrupted characters instead of the original Chinese text.

Environment:

• OS: Windows 11
• pi version: 0.60.0
• Terminal: Windows Terminal

Steps to Reproduce:

1. Start pi in interactive mode
2. Have the assistant respond with Chinese text (e.g., "你好，世界")
3. Run /copy to copy the last assistant message
4. Paste into any application (Notepad, browser, etc.)

Expected Behavior:
The Chinese characters should be copied correctly and paste as "你好，世界"

Actual Behavior:
The pasted text shows garbled characters (mojibake)

Root Cause Analysis:
The issue appears to be in the @mariozechner/clipboard native module (NAPI-RS/Rust based). On Windows, the clipboard API requires UTF-16 encoding, but the module may not be correctly converting UTF-8 input to UTF-16 before writing to the clipboard.

Workaround:
Using PowerShell as an alternative works correctly:

!powershell -Command "Set-Clipboard -Value 'Chinese text here'"

### Steps to reproduce

pi console output:  你好，世界

/copy

sublime text  view:  浣犲ソ锛屼笘鐣

### Expected behavior

_No response_

### Version

_No response_