Compose Multiplatform Rendering Pipeline: How Skia and CoreGraphics Interact on iOS Under Memory Pressure

Deep dive into how CMP's Skia-based rendering delegates to Metal on iOS, where the UIKitView boundary causes GPU context switches, how to profile layer rasterization with Xcode's Frame Debugger and Instruments, and the specific compositing decisions (offscreen buffers, layer opacity, clip paths) that trigger memory spikes on devices with 3GB RAM — with real measurements from a production app