Implement or review iPhone Duo multiple windows and Split View scenes, hinge-driven interactions (onHingeChange, UIHingeInteraction), and scene accessories such as CameraCaptureAccessory on the outer display, with explicit state ownership and handling for capability changes. Use when an app opens a second window, requests new scenes, reacts to the hinge angle or fold status, or shows content on the outer display while capturing on the inner display.
