VS Code: panel text stuck in narrow column after resize, does not reflow

Description

When using Claude Code in the VS Code extension, resizing the panel or opening files in adjacent editor groups causes the Claude Code output to get stuck rendering in a narrow column. The text does not reflow to the available width, making the session unreadable.

Steps to Reproduce

1. Open Claude Code in a VS Code editor tab (not sidebar)
2. Have an active conversation with markdown output (tables, code blocks, etc.)
3. Open a file in an adjacent editor group (e.g., package.json on the left) AND have the Explorer panel open on the right
4. The Claude Code tab gets squeezed between the file editor and the Explorer
5. Resize the window or maximize it to fullscreen

Expected Behavior

Claude Code content should reflow to fill whatever width is available in its tab, adapting dynamically as the panel is resized.

Actual Behavior

The text stays stuck at a narrow column width (~400px). Even after maximizing the VS Code window to fullscreen, the Claude Code content does NOT expand — it remains in the narrow column. The layout only partially recovers near the bottom of the scroll buffer.

This is especially bad with:

• Markdown tables (get truncated or wrap badly)
• Code blocks (horizontal overflow)
• Long lines of text (wrap to 2-3 words per line)

Screenshot

Will be attached as a comment below.

Environment

• OS: macOS Sequoia 15.5 (Darwin 24.6.0)
• VS Code version: <!-- run code --version and replace -->
• Claude Code extension version: <!-- check Extensions panel and replace -->
• Display: 2560x1664 Retina + 1920x1080 external