InventoryItemBuilder typedef
InventoryItemBuilder =
Widget Function(BuildContext context, InventorySlot slot, bool isSelected)
Renders one filled cell — isSelected reflects InventoryGrid.selectedSlotId
so the caller decides how to highlight it (this widget holds no
selection state of its own, see class doc).
Implementation
typedef InventoryItemBuilder =
Widget Function(BuildContext context, InventorySlot slot, bool isSelected);