File Tray group operations: click selects, ⌘-click toggles, ⇧-click selects a range, drag on empty space selects with a rubber band, and a drag carries every selected file. The context menu works on the whole selection (open, show in Finder, copy paths, select all, remove).
Dragging out of the File Tray now follows Finder rules: moves on the same disk, copies to another disk, ⌥ forces a copy, ⌘⌥ makes an alias. A moved file leaves the tray; copies and aliases stay staged.
