[BUG] Filenames stripped after submitting in VSCode extension

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?

As the title suggests, the filenames of images I upload are stripped and replaced with image.png. This makes it difficult for me to tell the agent which image I'm referring to when I'm comparing two screenshots, since both filenames are named identically.

<img width="713" height="97" alt="Image" src="https://github.com/user-attachments/assets/e723d3c5-6766-410c-bb72-00e60cad4711" />

What Should Happen?

The filenames should be preserved.

Error Messages/Logs

Steps to Reproduce

1. Upload two image files in the VS Code extension and type any message.
2. Observe that the filenames are displayed.
3. Press the submit button.
4. Observe that the filenames have been changed to image.png.

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

VSCode extension: 2.1.268

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_