Behavioral leaf widget for the toolbar item cell. Draws the empty-slot
sprite (0x060074CF) when unbound; draws the pre-composited icon texture
when a weenie is bound via SetItem(). ConsumesDatChildren=true prevents
the LayoutImporter from double-building the dat sub-elements. SpriteResolve
is configurable so paperdoll equip slots can swap in per-slot silhouettes
later. No Clicked/OnEvent — that wiring comes in Task 8 (ToolbarController).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>