Incorrect glyph rendering for certain characters (Latin and CJK) in Claude Code UI

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?

Some characters are rendered with incorrect or corrupted glyphs in the Claude Code input/output display area. Affected characters include certain English letters (e.g., h, y) and Chinese characters (e.g., 你), which appear as wrong symbols or stylized variants instead of the correct glyphs.

<img width="944" height="399" alt="Image" src="https://github.com/user-attachments/assets/222b79ba-747f-46ab-ab23-e4d0be4e5de3" />

What Should Happen?

All characters should render as their correct, standard glyphs without any visual distortion or substitution.

Error Messages/Logs

Steps to Reproduce

1. Open Claude Code (CLI or Desktop app)
2. Type any message containing the affected characters, e.g.: hi, could you help me? or a Chinese character like 你
3. Observe the rendered output in the UI

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

claude 2.1.145

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_