Desktop: file preview renders Markdown in a narrow column, long paragraphs and tables hard to read

Claude desktop app 2.31226.1 (Code tab), macOS 27.0.1.

When the file pane shows a Markdown file in preview mode, the rendered text is laid out in a column much narrower than the pane. A long paragraph wraps into many short lines, and a table with a few wide cells becomes a tall stack of wrapped text, so a file that is a readable status page in any other Markdown viewer is hard to read here. The pane itself is wide; the content does not use the width.

Steps:

1. Open a Markdown file that has a 150-word paragraph and a table with a long text cell in the file pane.
2. Switch to preview mode and widen the pane.
3. The text column stays narrow; the extra width is empty margin.

Expected: the rendered content uses the pane's width, or the maximum column width can be raised or turned off.