[BUG] VS Code "Toggle Maximized Panel" command flickers and fails when Claude Code extension is active

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report
• [x] I am using the latest version of Claude Code

What's Wrong?

The VS Code command workbench.action.toggleMaximizedPanel (Toggle Maximized Panel) does not work when the Claude Code extension is enabled.

When executed, the panel briefly flickers but immediately reverts to its original size — it never stays maximized.

Steps to Reproduce

1. Open VS Code with Claude Code extension enabled
2. Open the bottom panel (e.g. Terminal) with Cmd+J
3. Run Cmd+Shift+P → View: Toggle Maximized Panel
4. Expected: Panel maximizes to fill the editor area
5. Actual: Panel flickers briefly and snaps back to original size

Bisect Result

• code --disable-extensions . → Toggle Maximized Panel works correctly
• VS Code Extension Bisect (Help: Start Extension Bisect) identified anthropic.claude-code as the cause

Environment

• VS Code: 1.127.0
• Claude Code extension: v2.1.201
• OS: macOS (Darwin 25.5.0, Apple Silicon)
• claudeCode.preferredLocation: panel