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.cpp

@@ -94,23 +94,28 @@ namespace nativetouch::transform {
         return overlay::OVERLAY->transform_touch_point(&position->x, &position->y);
     }
 
-    // the digitizer is mapped to the zero-based primary display, while SDVX
-    // still expects portrait coordinates when its image is rendered in landscape:
+    // SDVX still expects portrait coordinates when its image is rendered in landscape:
     // (x, y) -> (width * (1 - y / height), height * x / width).
+    bool sdvx_landscape_rotate(POINT *position, LONG width, LONG height) {
+        if (width <= 0 || height <= 0) {
+            return false;
+        }
+
+        const auto input_x = position->x;
+        position->x = width - MulDiv(position->y, width, height);
+        position->y = MulDiv(input_x, height, width);
+        return true;
+    }
+
+    // the digitizer is mapped to the zero-based primary display, so the contact is already
+    // in the effective landscape resolution the rotation is based on
     static bool transform_sdvx_landscape_touch_position(POINT *position) {
         const auto landscape_width = static_cast<LONG>(GRAPHICS_FS_CUSTOM_RESOLUTION.has_value() ?
             GRAPHICS_FS_CUSTOM_RESOLUTION.value().first : GRAPHICS_FS_ORIGINAL_HEIGHT);
         const auto landscape_height = static_cast<LONG>(GRAPHICS_FS_CUSTOM_RESOLUTION.has_value() ?
             GRAPHICS_FS_CUSTOM_RESOLUTION.value().second : GRAPHICS_FS_ORIGINAL_WIDTH);
-        if (landscape_width <= 0 || landscape_height <= 0) {
-            return false;
-        }
 
-        const auto input_x = position->x;
-        position->x = landscape_width -
-            MulDiv(position->y, landscape_width, landscape_height);
-        position->y = MulDiv(input_x, landscape_height, landscape_width);
-        return true;
+        return sdvx_landscape_rotate(position, landscape_width, landscape_height);
     }
 
     // convert physical screen coordinates to game touch coordinates for a known target

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);