CMS editor: opening an .mdx file gets an error

```
## Error Type
Console Error

## Error Message
In HTML, cannot be a descendant of .
This will cause a hydration error.

...


, ...}} ...>

type="button"
> role="tab"
> aria-selected={true}
> aria-controls="editor-panel-0"
> onClick={function onClick}
> onMouseDown={function onMouseDown}
> className="group flex items-center gap-1.5 px-3 py-1.5 text-xs font-mono rounded-t trans..."
> >


> type="button"
> onClick={function onClick}
> className="ml-1 p-0.5 rounded text-[var(--color-text-dim)] hover:text-[var(--color-err..."
> aria-label="Close glossary.ts"
> >
...
...
...
...
...

at button (:null:null)
at (components/cms/FileEditor.tsx:359:13)
at Array.map (:null:null)
at FileEditor (components/cms/FileEditor.tsx:335:16)
at CMSPage (app/admin/(dashboard)/cms/page.tsx:740:13)

## Code Frame
357 | />
358 | )}
> 359 | {
362 | e.stopPropagation()

Next.js version: 16.1.4 (Turbopack)
```