sdvx: fix api touch and -sdvxnosub sub window (#868)

## Link to GitHub Issue or related Pull Request, if one exists
Related: #859 and #862.

## Description of change

Three SDVX (Valkyrie model) fixes:

* **API touch went to the wrong window.** SDVX registers touch on both
its Main Screen and Sub Screen windows, and the native injector kept
whichever attached last. The touch surface is now published explicitly:
sub screen window when windowed, main window in fullscreen.
* **Landscape never rotated API coordinates.** Synthetic contacts bypass
`transform::hardware_to_game`, so they missed the rotation a real finger
gets. Applied before injection now, as portrait already did. Extracted
to `sdvx_landscape_rotate` so both paths share it; gated on the native
path since `wintouchemu` rotates via the subscreen overlay instead.
* **`-sdvxnosub` didn't hide the sub window in fullscreen.**
`ShowWindow_hook` had branches for GITADORA, pop'n and IIDX but not
SDVX. Added the missing one.

## Testing
Tested Nabla

src/spice2x/touch/native/transform.h

@@ -10,6 +10,7 @@ namespace nativetouch::transform {
     };
 
     bool is_tdj_dedicated_subscreen(HWND window);
+    bool sdvx_landscape_rotate(POINT *position, LONG width, LONG height);
     bool game_to_screen(HWND window, POINT *position);
     bool screen_to_game(HWND window, POINT *position);
     bool mouse_to_game(HWND window, POINT *position);