corregit el escalat de finestra i mode fullscreen

source/game/options.hpp

@@ -10,7 +10,7 @@ struct Window {
         int width{640};
         int height{480};
         bool fullscreen{false};
-        int size_increment{100};  // Increment per F1/F2
+        float zoom_factor{1.0f};  // Zoom level (0.5x to max_zoom)
 };
 
 struct Physics {