Orga: next refinement

[kulmann]

This is a meta-issue collecting the issues for the next refinement. We won't keep a history. Just the list of to-be-refined issues.

• [design-system] Replace custom size type with tailwind classes #2820

[JammingBen]

Not sure if those 2 stories fit into a refinement yet because they kinda need further conceptualizing, but since the stable release is now out, we should not lose sight of them:

• Make the topbar less prominent #2348
• Display folder actions in blank line below the breadcrumbs #2590