[BUG] broken CJK text on running

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

https://github.com/user-attachments/assets/4e1b65d5-a107-4a70-83cd-504246036f89

when claude is working on a task, the CJK (in this case, Korean) text gets constantly broken into gibberish

What Should Happen?

they shouldn't.

Error Messages/Logs

Steps to Reproduce

1. open claude
2. make a request in CJK e.g yarn typecheck 실행해
3. see that the output is garbled

Claude Model

Sonnet (default)

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

2.0.58 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_