VS Code Extension Leaves Blank Window Artifact After Restart

Environment:

• OS: Linux
• VS Code with Claude Code extension

Steps to Reproduce:

1. Open VS Code in a project directory
2. Click "Run Claude Code" button (upper right)
3. New terminal opens, Claude runs normally
4. Close VS Code entirely (click X on main window)
5. Restart VS Code from same directory

Expected Result:
VS Code opens normally without artifacts

Actual Result:
A blank window with no controls (except close button) appears on the right side and must be manually closed each time

Impact:
This artifact persists every time VS Code is restarted after using Claude Code, requiring manual cleanup

Workaround:
Manually close the blank window each time

This appears to be a window management issue where the extension isn't properly cleaning up its UI state when VS Code shuts down.