fix: disable smooth scroll under reduced motion; drop dead motion exports

lib/motion.ts

@@ -9,11 +9,6 @@ export const fadeInUp: Variants = {
   visible: { opacity: 1, y: 0, transition: { duration: 0.5, ease: easeOutExpo } },
 };
 
-export const fadeIn: Variants = {
-  hidden: { opacity: 0 },
-  visible: { opacity: 1, transition: { duration: 0.4, ease: easeOutExpo } },
-};
-
 export const staggerContainer: Variants = {
   hidden: {},
   visible: { transition: { staggerChildren: 0.1 } },