Publish Chimera GFX source

docs/phase1/VIDEOOUT_CLEAR_EXPERIMENT.md

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+# Minimal VideoOut clear-frame experiment
+
+## Goal and non-goals
+
+Display exactly one fixed 1920x1080 solid frame through the existing pinned
+PS5 SDL2 CPU-framebuffer backend, hold it for one second, and cleanly release
+SDL. This experiment does not use `libchimera-gfx` hardware contexts, GNM,
+shaders, command buffers, compute, custom tiling code, input, audio, OpenGL,
+OSMesa, or a render loop.
+
+## Application sequence
+
+Project code performs the following calls only after exact compile-time and
+runtime firmware identifiers match and the literal acknowledgement is present:
+
+1. `SDL_SetMainReady`
+2. `SDL_Init(SDL_INIT_VIDEO)`
+3. `SDL_CreateWindow`
+4. `SDL_GetWindowSurface`
+5. `SDL_MapRGBA`
+6. `SDL_FillRect`
+7. `SDL_UpdateWindowSurface` exactly once
+8. `SDL_Delay(1000)`
+9. `SDL_DestroyWindow`
+10. `SDL_Quit`
+
+The fixed color is RGBA `(0x18, 0x2a, 0x41, 0xff)`. Logs contain stage names
+and booleans only.
+
+## Indirect pinned-SDL behavior
+
+At commit `0baf4ac49382b537ba449901b5b6d0d189bb1fbb`, the reviewed PS5 video
+backend indirectly uses these public export names:
+
+- initialization: `sceSystemServiceHideSplashScreen`, `sceVideoOutOpen`,
+  `sceKernelAllocateMainDirectMemory`, `sceKernelMapDirectMemory`,
+  `sceKernelCreateEqueue`, `sceVideoOutAddFlipEvent`,
+  `sceVideoOutSetFlipRate`, `sceVideoOutSetBufferAttribute2`, and
+  `sceVideoOutRegisterBuffers2`;
+- single present: `sceVideoOutSubmitFlip` and `sceKernelWaitEqueue`;
+- cleanup: `sceVideoOutDeleteFlipEvent`, `sceVideoOutClose`,
+  `sceKernelReleaseDirectMemory`, and `sceKernelDeleteEqueue`.
+
+These are indirect implementation observations, not independently proven
+`chimera-gfx` ABI declarations. The overlay removes keyboard and IME setup.
+
+## Build boundary
+
+`tools/build-phase1-videoout.sh` verifies both upstream commits, stages the
+reviewed SDL overlay, disables SDL2main plus unrelated SDL subsystems, and
+cross-compiles the probe and candidate. It then statically requires the exact
+15-name Sce import inventory above and zero GNM, keyboard, IME, or UserService
+imports. It contains no upload, run, host, port, or boot command. The default
+firmware identifier is `NONE`.
+
+## Known blocker
+
+The pinned SDL backend waits inside `sceKernelWaitEqueue` with no publicly
+proven bounded timeout in this call path. Project code cannot safely cancel
+that wait. The artifact is suitable for offline inspection, but not yet for
+hardware authorization until `HARDWARE_TEST_PLAN.md` records an accepted
+supervisor/recovery mechanism and an exact firmware.