[BUG] Italic markdown rendering clips final character(s) in PowerShell terminal — letter d common offender

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?

Description:
When Claude Code renders italic markdown in the CLI (e.g., should, field), the final one or two characters of the italicized word are occasionally dropped or not rendered. The issue is
reproducible in PowerShell on Windows and appears to be letter-specific, with d at the end of an italic span being the most frequently observed case.

Expected behavior: should renders as should

What Should Happen?

Actual behavior: renders as shoul (the d is dropped)

<img width="1904" height="619" alt="Image" src="https://github.com/user-attachments/assets/c205d9fe-7800-4f08-89e3-69a28ae5ae03" />

<img width="1904" height="619" alt="Image" src="https://github.com/user-attachments/assets/2bbd4e9e-066e-4493-8c62-910f92ee2956" />

Error Messages/Logs

Notes:
  Likely caused by PowerShell's incomplete ANSI italic escape code support (\e[3m / \e[23m). The escape sequence may be shifting the column count, causing the terminal to drop the displaced
  character at the line boundary. PowerShell on Windows Terminal is probably the most common Windows deployment environment for Claude Code — this affects real daily usage.

  ---
  Just paste that in as a new issue at https://github.com/anthropics/claude-code/issues and you're good.

Steps to Reproduce

Steps to Reproduce:

1. Open Claude Code in a PowerShell terminal
2. Ask a question that produces a response with italicized words ending in d (e.g., should, ield, workaround)
3. Observe that the final character(s) of the italic span do not render — the word appears truncated

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Sonnet 4.6 — model ID claude-sonnet-4-6

Platform

AWS Bedrock

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_