it occurred to me that by making border stretchable we could avoid the dotted border problem.

it does lead to a slight odd "center highlight" effect on the top (again due to QSvgRenderer getting the size of this element wrong) but it looks way better; this svg will still suck for panels on the top, left or right because you'll just get a black border...

but then since when was artwork in plasma ever something anyone actually paid any concern over. =(