feat(input): binding START per jugador (teclat 1/2 fix, mando remapejable; pausa només per F11)

source/core/input/gamepad_bindings.hpp

@@ -25,6 +25,7 @@ class GamepadBindings {
         JUMP,
         ATTACK,
         SERVICE,
+        START,
     };
 
     // Triggers L2/R2 representats com a "botons virtuals" — replica la