[BUG] Sidebar panel does not resize when dragging the sidebar edge

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?

The Claude Code panel in the VS Code sidebar does not respond to sidebar width changes when the user drags the sidebar edge to resize it.
Instead of reflowing to fit the new width, the panel stays at a fixed (often very small) size and does not scale with the container.

<img width="1129" height="1298" alt="Image" src="https://github.com/user-attachments/assets/96516d84-578b-481e-98f7-ff0864d9502a" />

What Should Happen?

The Claude Code panel should reflow and scale responsively to match the new sidebar width.

Error Messages/Logs

Steps to Reproduce

1. Open Claude Code in the VS Code sidebar.
2. Hover over the right edge of the sidebar until the resize cursor appears.
3. Drag the edge to make the sidebar narrower or wider.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Vscode Plugin: 2.1.195

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_