fix(audio,windows): adapt Raw Input + hook backends to windows-rs 0.54 API shape

Initial Task C commit (77c2a1d) used handle constructors and import paths
that match windows-rs 0.58+, not the 0.54 version pinned via the
workspace's transitive 'windows' dep. Compile errors on the Korean
Windows 11 build:

  * HWND/HHOOK/HRAWINPUT take 'pub isize' in 0.54 (became raw pointers
    in 0.58). Use HWND(HWND_MESSAGE_PTR), HHOOK(0), HRAWINPUT(lparam.0)
    instead of *mut _ casts.
  * CreateWindowExW returns HWND directly in 0.54, not Result<HWND>.
    Check hwnd.0 == 0 for null.
  * RegisterClassExW + WNDCLASSEXW are gated behind Win32_Graphics_Gdi
    in 0.54. Added that feature.
  * XBUTTON1 / XBUTTON2 live in Win32::UI::WindowsAndMessaging not
    Win32::UI::Input::KeyboardAndMouse in 0.54.
  * Win32_System_Threading needed for GetCurrentThreadId.
  * Unused Mutex import dropped.

No behavioural change relative to 77c2a1d; just signature alignment.

crates/chanora_audio/Cargo.toml

@@ -41,7 +41,9 @@ ndk-context = "0.1"
 # require a per-backend OS thread that owns a message pump.
 windows = { version = "0.54", features = [
     "Win32_Foundation",
+    "Win32_Graphics_Gdi",
     "Win32_System_LibraryLoader",
+    "Win32_System_Threading",
     "Win32_UI_Input",
     "Win32_UI_Input_KeyboardAndMouse",
     "Win32_UI_WindowsAndMessaging",