[BUG] During tool usage, claude code does not terminate a underline

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?

This could be an issue with my setup (without much detail, iTerm2 using lillex nerd font). During some tools usages (I have not found which) everything in the output is underlined. It looks like an ANSI escape is not happening after opening one for an underline style.

<img width="754" height="125" alt="Image" src="https://github.com/user-attachments/assets/3deb1bd1-5930-4f3f-aa25-68a3edaa4ade" />

What Should Happen?

Underline ANSI terminated.

Error Messages/Logs

Steps to Reproduce

1. Basic tool usage. Maybe the search result started a ANSI underline. or results from web fetch aren't escaped for ANSI series delimiters

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.0.69 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

iTerm2

Additional Information

_No response_