v0.4.6

Fixed

• Dragging a scene tile to reorder it, added in 0.4.5, never actually started a
  drag in the notarized build: a Button's own click gesture and .onDrag's
  drag-start gesture compete for the same mouse-down on macOS, and the Button
  always won. Tiles are no longer Buttons — they behave like one for click,
  keyboard and VoiceOver, but no longer block the drag. Move Left/Right in the
  context menu was unaffected and worked all along.