Make sure the panel cannot be smaller than the margins of the panel svg
This uses https://invent.kde.org/frameworks/plasma-framework/-/merge_requests/647 and plasma-workspace!2329 (merged)
This reads the minimum size the panel can be drawn at in the Panel view (so that it can be read by the panel cpp code) and makes sure that the thickness box cannot set a value that's lower than that. Even if you change to a theme that has min size bigger than current panel thickness, the value will update so that it's never lower than it (since we re-check the thickness every time the min size changes, see plasma-workspace!2329 (diffs)).
How to test: switch to WhiteSur-Dark theme and confirm that the panel cannot be smaller than 32px
Edited by Niccolò Venerandi