4-task TDD plan for Sub-phase A: UiRoot named-window registry
(Show/Hide/Toggle/BringToFront) + raise-on-click + F12 wiring of the
existing ToggleInventoryPanel action to a throwaway placeholder inventory
window that Sub-phase B replaces. Divergence handled by extending IA-12.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
