VS Code extension: Session rename reverts to auto-generated name after navigating away

Description

When renaming a session in the sidebar, the custom name appears to save but reverts to the auto-generated name when navigating away.

Steps to reproduce

1. Open Claude Code in Antigravity (VS Code-based editor)
2. In the session sidebar, hover over a session and click the pencil (edit) icon
3. Type a custom name for the session
4. Press Enter - the new name appears and looks saved
5. Click on a different session or interact with the UI elsewhere
6. Navigate back to the renamed session - the name has reverted to the auto-generated name

Expected behavior

The custom session name should persist after pressing Enter, even when navigating between sessions or restarting the editor.

Actual behavior

The renamed session name displays correctly immediately after pressing Enter, but reverts to the auto-generated name as soon as the user navigates to another session or otherwise interacts with the sidebar. This makes it impossible to organize sessions with custom names.

Environment

• Claude Code version: 2.1.81
• Platform: macOS (Darwin 25.1.0)
• Editor: Antigravity (based on VS Code)

Notes

The behavior is consistent and reproducible on every attempt. The rename never persists regardless of how many times it is retried. This occurs specifically in Antigravity, which is based on VS Code, so it may also affect the standard VS Code extension.