Spatial/grid inventory framework, inventory sounds

Early steps toward a spatial grid-based inventory like many ARPGs.
This first pass has placement validation, auto placement and auto-rotation, drag and drop movement, resale, tooltips.

A lot left to do - next steps will include spatial shop grid with category tabs, drag placement preview indicator (red and green for validity), drag and drop to purchase and equip, improved tooltip popup design, active hotkey icon etc

Видео Spatial/grid inventory framework, inventory sounds канала Boondie