Forward mouse + keyboard to DirectInput and Raw Input games

The MKB subsystem covered message-loop (PostMessage) and polling
(GetAsyncKeyState/GetKeyboardState/GetCursorPos) games. Add the two remaining
read paths, both fed from the same synthesized state:

- DirectInput: vtable-swap IDirectInputDevice8::GetDeviceState (a COM method ->
  vtable swap, not inline, per the x86 COM-prologue trap), reading the shared
  vtable from a kept-alive probe device (the game made its devices before we
  injected). Dispatch on cbData: 256 = keyboard BYTE[256] indexed by DIK
  scan-code (map VK->DIK via MapVirtualKey VK_TO_VSC); DIMOUSESTATE = mouse
  buttons + relative deltas from the forwarded cursor.
- Raw Input: games get no WM_INPUT while unfocused, so mkb_pump synthesizes it
  (PostMessage WM_INPUT with lParam = one of our RAWINPUT slots) and the hooked
  GetRawInputData serves that slot back (RID_HEADER + RID_INPUT). Covers keys +
  buttons; relative raw-mouse movement isn't in the position-based MKB stream.

Both detours use the DetourGate safe-unhook guard, and the mock_game_test storm
exercises their install/remove. dinput_hook_test drives the real path end-to-end:
forward a key + mouse button through the ring, then a real DI keyboard/mouse
device's GetDeviceState returns them. The Raw Input round-trip is operator-
validated against a real game (too brittle to assert in-process). vtable_hook.hpp
factors the COM vtable-swap helper out for reuse.

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

tests/CMakeLists.txt

@@ -14,6 +14,24 @@ target_link_libraries(hook_selftest PRIVATE
 
 add_test(NAME hook_selftest COMMAND hook_selftest)
 
+# In-process self-test for the DirectInput forwarding path: reuses mkb_hook.cpp, installs the MKB
+# hooks (which vtable-swap IDirectInputDevice8::GetDeviceState), forwards a synthetic key + mouse
+# button through the ring, then creates a real DI keyboard + mouse device and asserts GetDeviceState
+# returns the forwarded input. Skips cleanly if DirectInput can't acquire a device.
+add_executable(dinput_hook_test
+	dinput_hook_test.cpp
+	${CMAKE_SOURCE_DIR}/hook/src/mkb_hook.cpp
+	${CMAKE_SOURCE_DIR}/hook/src/hook_registry.cpp)
+target_include_directories(dinput_hook_test PRIVATE ${CMAKE_SOURCE_DIR}/hook/src)
+target_link_libraries(dinput_hook_test PRIVATE
+	coop_common
+	safetyhook::safetyhook
+	user32
+	dinput8
+	dxguid
+	ole32)
+add_test(NAME dinput_hook_test COMMAND dinput_hook_test)
+
 # Unit test for the shared audio ring (lock-free SPSC push/pop, wrap-around,
 # format handshake, overrun policy). Header-only, no hook or audio device.
 add_executable(audio_ring_test audio_ring_test.cpp)
@@ -242,6 +260,7 @@ add_test(NAME ui_fit_test COMMAND ui_fit_test)
 # test's "coop_tone.exe alongside me" lookup keeps working.
 coop_output_subdir(tests
 	hook_selftest
+	dinput_hook_test
 	audio_ring_test
 	mkb_ring_test
 	mkb_map_test