[BUG] /copy command does not preserve Unicode on Windows

What's Wrong?

Claude output containing Unicode characters (notably Unicode m-dash, but others as well) is not properly copied to the clipboard by /copy

Displayed text: (captured by "write it to a file please")

# Unicode Test

- Section § sign
- Em dash — vs regular hyphen -
- En dash – vs regular hyphen -
- Bullet • dot
- Curly quotes "hello" vs straight "hello"
- Ellipsis … vs three dots ...
- Arrow → and ←
- Multiplication × sign
- Check mark ✓ and cross ✗
- Copyright © and trademark ™

Results of /copy:

# Unicode Test

- Section § sign
- Em dash ΓÇö vs regular hyphen -
- En dash ΓÇô vs regular hyphen -
- Bullet ΓÇó dot
- Curly quotes "hello" vs straight "hello"
- Ellipsis … vs three dots ...
- Arrow → and ←
- Multiplication × sign
- Check mark Γ£ô and cross Γ£ù
- Copyright © and trademark ™

What Should Happen?

/copy should copy the correct Unicode to the clipboard.

# Unicode Test

- Section § sign
- Em dash — vs regular hyphen -
- En dash – vs regular hyphen -
- Bullet • dot
- Curly quotes "hello" vs straight "hello"
- Ellipsis … vs three dots ...
- Arrow → and ←
- Multiplication × sign
- Check mark ✓ and cross ✗
- Copyright © and trademark ™

Steps to Reproduce

1. Ask Claude Code to generate some Unicode sample text
2. Execute /copy
3. Paste the text somewhere, including back into Claude

Claude Code Version

2.1.68 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal