cpu start

examples/example_apple_cpu/README.md

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+# How to Build
+
+## macOS
+
+Use the provided `Makefile` or directly:
+```sh
+clang++ -std=c++11 -ObjC++ -fobjc-arc -I ../.. -I ../../backends \
+  main.mm ../../backends/imgui_impl_osx.mm ../../backends/imgui_impl_cpu.cpp ../../imgui*.cpp \
+  -framework Cocoa -framework GameController \
+  -o example_apple_cpu
+```
+
+This example uses Cocoa + `imgui_impl_osx` for windowing/input and `imgui_impl_cpu` for rendering.
+It renders to a native BGRA CPU framebuffer and does not use SDL.