Draft: Drop panel toolbox
Since 339e3a1c when in edit mode, the panel could be configured by clicking anywhere on the panel. This makes the toolbox to enter panel configuration redundant. It's impossible to click it without getting the blue highlight for the whole panel and being clear we're going through a new path.
Having something in the panel whilst a user is trying to set the sizes of things in the panel is a problematic design.
The context menu is unaffected.