[BUG] /heapdump fails with EEXIST 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?

/heapdump command fails on Windows with EEXIST error. The status bar shows "High memory usage (7GB) · /heapdump" suggesting users run the command, but it always fails on Windows regardless of the working directory.

<img width="1100" height="381" alt="Image" src="https://github.com/user-attachments/assets/f6374464-664e-4f62-957d-d23a1969ea90" />

What Should Happen?

/heapdump should either successfully create a heap dump file, or not be surfaced to users if it doesn't work on Windows (e.g., the "High memory usage · /heapdump" suggestion in the status bar should not appear on unsupported platforms).

Error Messages/Logs

Failed to create heap dump: EEXIST: file already exists, mkdir 'C:\Users\{user}\Desktop'

Steps to Reproduce

1. Run claude on Windows
2. Run heapdump
3. Error is returned immediately (reproducible in any working directory)

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.72

Platform

Other

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_