A drag takes only the material it starts on (Shift: everything). The blow
selection is the hand: click or Q/E for one material, Ctrl+click for a mix.
Empty materials leave the hand, an empty hand blows nothing, and a pickup
fills an empty hand. Removes the pick-up marks and the F vacuum menu.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
