createState method
Creates the state object for this CardCarousel widget.
Returns an instance of _CardCarouselState, which manages the scroll controller
and builds the interactive carousel layout. This override is required for
StatefulWidget to handle dynamic scroll listening and gradient animations.
Returns: _CardCarouselState - The state managing scroll and visual effects.
Implementation
@override
State<CardCarousel> createState() => _CardCarouselState();