Concepts: lists glide on the wheel, room below the assets (#309)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Concepts.md

@@ -314,6 +314,10 @@ sharp; a sprite larger than the group is shrunk to fit.
 The asset panel and **Scene objects** share the left column; the divider between them drags
 the height from one to the other, and dragged all the way either keeps its header. The split is a
 share of the column, so a taller or shorter window keeps it.
+Both lists glide on a wheel step instead of jumping, as long as the zoom transition takes (see
+below); quick steps add up, and dragging the bar or a jump to a row ends the glide where it is.
+Below the last row the asset panel always keeps room for six more, so its end can be scrolled up
+away from the bottom edge; clicks and the context menu there work as on any empty part of the list.
 
 **Panel sizes are remembered.** Every divider stays where it was dragged, after a reload too: the
 ones left and right of the centre column, the one above the console, the one in the left column,