Problems with HTMLFileEditor

I just realised after my edit to add the troubleshooting details, that the repro was using 2024.2. I’ve updated it to 2025.1 EAP, and now I see the original bug - when the HTML pane is dragged from one tab group to another, the reload no longer works, and it looks like the editor scale is messed up - the HTML content appears much larger than in the original editor.