Fix Rotation with Pointer and Lightgun Devices

The rotation applied at draw time — DrawLibretroTint (and DrawLibretroPro/DrawLibretroEx) rotate the framebuffer texture on screen via DrawTexturePro. But the input side, LibretroInputState, maps the mouse straight from raw screen coordinates into the core's native (unrotated) coordinate space:

RETRO_DEVICE_POINTER (2260-2262) — GetMouseX()/GetScreenWidth() → [-1, 1]
RETRO_DEVICE_LIGHTGUN screen X/Y (2194-2197) — same
The core thinks in its own framebuffer space. Once you visually rotate the display, screen-space no longer lines up with core-space, so a pointer/lightgun tap lands in the wrong place. To be correct, the screen→core transform needs to invert the display rotation:

0°: (cx, cy) = ( sx, sy)
90° CW: (cx, cy) = ( sy, -sx)
180°: (cx, cy) = (-sx, -sy)
270° CW: (cx, cy) = (-sy, sx)

For the relative mouse (RETRO_DEVICE_ID_MOUSE_X/Y and lightgun X/Y deltas at 2172-2175), the deltas should strictly also be rotated, but it matters far less — relative motion is rarely used with display rotation, and most cores don't expect it.

Two caveats worth noting, since they compound the pointer problem:

The mapping already uses full screen width/height, not the actual letterboxed destination rect that DrawLibretroTint computes (visW/visH). So absolute pointing is already off whenever there are letterbox bars — rotation just makes it more visibly wrong (and 90/270 swaps which axis the bars are on).
A fully correct fix would map mouse → dest-rect → un-rotate → normalize, which means the input code needs access to the same dest-rect/rotation math DrawLibretroTint does.

Fix it.

Start in raylib-libretro.h at LibretroInputState and the RETRO_DEVICE_POINTER/lightgun mappings around lines 2087, 2172-2197, then compare them with DrawLibretroTint and its visW/visH destination-rect calculation around lines 2986-3009. Trace the existing rotation and letterboxing math first; done means absolute pointer and lightgun coordinates align across all four rotations and letterboxed displays.