[BUG] Markdown renderer incorrectly treats single tilde (~) as strikethrough

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?

Single tildes used for "approximately" (e.g., ~15M minutes) are being rendered with strikethrough formatting in the markdown viewer, when they should just display as plain text

What Should Happen?

Expected behavior: Single tilde should display as "approximately" symbol
Actual behavior: Text appears with strikethrough formatting

Error Messages/Logs

Steps to Reproduce

create markdown with ~test~ and see if it generates strikethrough

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.0.20

Claude Code Version

2.0.21 (Claude Code)

Platform

AWS Bedrock

Operating System

Windows

Terminal/Shell

WSL (Windows Subsystem for Linux)

Additional Information

_No response_