concinnity-device 0.18.65

GPU backends (Metal, Vulkan, DirectX) behind a device facade for Concinnity
Documentation

The device backends. The proprietary, hardware-facing renderers - Metal (macOS), DirectX 12 (Windows), Vulkan (Windows/Linux) - plus the shared native Win32 window/input layer. Exactly one backend compiles per build (resolved by build.rs into a single backend_* cfg). Depends on concinnity-render (the RenderBackend/SceneControl trait seam + render-prep) and concinnity-core; owns no gameplay, ECS-runtime, audio, or physics. The client drives these through a Box<dyn RenderBackend> obtained from init_backend, never naming a concrete context type.