[BUG] [App] No way to download files from a Claude Code on the web sandbox without a git repo

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?

In a non-git Claude Code on the web session, files generated by Claude (e.g. an HTML deliverable, a tarball in /tmp) have no first-class download path. Options today are: /teleport (requires a clean git repo + pushed branch), gh gist (requires gh auth in the sandbox, often missing), or pasting file contents as a chat code block. There's no "download this file" / artifact panel for arbitrary sandbox files. Expected: a download/open-file UI affordance for files at known paths (e.g. /tmp/, /home/claude/repo/).

Sorry if this is not the best repo to report this but I couldn't easily find a better one.

What Should Happen?

I'd expect Claude Code to be able to give me a file to download same way as Claude Chat does.

Seems like a claude_artifact tool is missing.

Error Messages/Logs

Steps to Reproduce

1. Continue a session from Claude Design
2. ask Claude to give you a file

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

Claude Web and desktop app

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Other

Additional Information

_No response_