The editor's top row becomes the 40px strip: Library on the left, the
quick switcher centered on it at 30px, Discord on the right. The map card
leaves the bar and joins the toolbar in a column at the canvas top-left, so
the canvas runs up to the seam and every floating panel keeps its own 8px of
air. Two layout tests pin the strip's height and center line.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>