[BUG] Numerous dropped/hidden characters in terminal display

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?

Numerous dropped/hidden characters in terminal output.

This appears to affect all character types randomly(i) throughout the display output, not just specific ascii codes. It appears worst in "styled" sections of text (bolded, highlighted, colored, etc), but can be observed with some regularity in any terminal output from claude.

(i) Note that by randomly I mean that the precise characters that are affected change from claude instance to claude instance, but then are consistent for that instance of claude code.

Examples of corrupted terminal output:
<img width="1417" height="155" alt="Image" src="https://github.com/user-attachments/assets/d27e49d7-6c47-4a38-b53a-5ae74942bfba" />

<img width="429" height="32" alt="Image" src="https://github.com/user-attachments/assets/3ddf6b3b-2234-4e3f-a5b5-d0898a4172ce" />

<img width="812" height="76" alt="Image" src="https://github.com/user-attachments/assets/b7b37f13-3d01-49ec-b5bc-dab0583573ad" />

<img width="563" height="46" alt="Image" src="https://github.com/user-attachments/assets/6d1819b8-ee08-4ee4-b6e6-602c073fa3b1" />

What Should Happen?

All characters should be rendered so that output can be read without having to guess at missing text.

Error Messages/Logs

Steps to Reproduce

1. send claude code a task
2. observe that random characters in claude's terminal output will simply be missing, rendering as just a space.

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.6x

Claude Code Version

2.1.72

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_