Thicken root node of collapsed clades

This is a small corner case, but when clade collapsing is done it looks like the root nodes of collapsed clades are not thickened (even though they are assigned a color). I think the expected behavior is that these nodes should be thickened?


Start by reproducing the collapsed-clade case shown in the attached GIF, then trace the clade-collapsing rendering path to the code that assigns color and thickness to root nodes. Done means the root nodes of collapsed clades are visibly thickened while retaining their assigned color.

Written by the indexing model from the issue text.