[BUG] Display rendering bug with Japanese text on Windows

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?

Japanese text displays with large gaps and strange spacing in the terminal output.

What Should Happen?

## Description
Japanese text displays with large gaps and strange spacing in the terminal output.

## Environment

• OS: Windows
• Terminal: Windows Terminal
• Claude Code version: (run claude --version to check)

## Screenshot

<img width="1479" height="733" alt="Image" src="https://github.com/user-attachments/assets/6662f7d2-8ac6-4d98-bd5e-d38201b72380" />

Error Messages/Logs

Steps to Reproduce

## Steps to reproduce

1. Start Claude Code on Windows
2. Have a conversation in Japanese

gned characters

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.0.73 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_