Add mock-game capture/audio/hook stress test

mock_game_test launches coop_mock_game (DX11/DX12, frame-numbered A/V), injects
coop_hook.dll, opens the hook's shared video texture, and decodes the frame
number from the captured pixels to assert a monotonic, advancing mirror for
both backends (catches dropped/stale/out-of-order frames). Then it runs an
A/V + hook/unhook stress pass and confirms no crash + capture resumes. Adds a
read_pixel() readback to the shipping SharedTextureSource for the decode.
Robust to repeated/CI runs (kills stray games, retries inject). Trim the
roadmap (the mock-game item is done) and document the test.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/CMakeLists.txt

@@ -140,6 +140,20 @@ target_link_libraries(dx12_present_hook_test PRIVATE
 
 add_test(NAME dx12_present_hook_test COMMAND dx12_present_hook_test)
 
+# Comprehensive capture/audio/hook stress test against coop_mock_game: launches the
+# animated, frame-numbered A/V game, injects coop_hook.dll, decodes captured frame
+# numbers (DX11 + DX12) to assert a monotonic/advancing mirror, checks audio capture, and
+# stresses hook/unhook cycles. Reuses the shipping shared-texture reader. Skips without D3D11.
+add_executable(mock_game_test
+	mock_game_test.cpp
+	${CMAKE_SOURCE_DIR}/host/src/capture/shared_texture.cpp)
+target_include_directories(mock_game_test PRIVATE
+	${CMAKE_SOURCE_DIR}/host/src
+	${CMAKE_SOURCE_DIR}/tools/mock_game)
+target_link_libraries(mock_game_test PRIVATE coop_common d3d11 dxgi)
+add_dependencies(mock_game_test coop_mock_game coop_hook)
+add_test(NAME mock_game_test COMMAND mock_game_test)
+
 # In-process self-test for the OpenGL capture path. Reuses the shipping
 # opengl_hook.cpp and drives a real OpenGL context in the same process, so it
 # exercises the SwapBuffers hook, the glReadPixels readback, and the upload into
@@ -178,4 +192,5 @@ coop_output_subdir(tests
 	srgb_format_test
 	present_hook_test
 	dx12_present_hook_test
-	opengl_hook_test)
+	opengl_hook_test
+	mock_game_test)