Previously, sticky scroll headers were painted on top of the main
editor. This works, but only if the editor background is a solid color

Bad:
<img width="603" height="319" alt="image"
src="https://github.com/user-attachments/assets/bf438003-a416-46a6-85bc-dfa767be067e"
/>


Good:
<img width="603" height="319" alt="image"
src="https://github.com/user-attachments/assets/e644e54a-6667-41e1-86d0-16e659bea844"
/>

Release Notes:

- Fixed: Editor no longer renders behind sticky scroll headers while
using a transparent theme