feat: add Carousel component

[braianj]

Adds a generic, composition-based Carousel primitive. Consuming apps (sites) hand-roll and re-import a single carousel implementation across several surfaces (Home rows, Create sections); this promotes it into the shared library so it stops living in app code.

Behavior:

• Infinite loop via a tripled-item track (clone → real → clone) with an imperceptible snap back into the real range on transition end.
• Drag/swipe (mouse + touch), with a click-suppression guard so a drag doesn't trigger slide clicks.
• Autoplay that pauses when the tab is hidden (visibilitychange); autoplayDelay={0} disables it.
• Dot pagination and desktop hover nav buttons.

Composition over configuration: the consumer owns each slide through renderItem / keyExtractor, so the carousel carries no domain knowledge. Responsive slide geometry uses ui2's own useDesktopMediaQuery and theme breakpoints; colors come from theme tokens.

Generic public API (Carousel, CarouselProps<T>) exported through src/index.ts. Additive; no existing component or type changed.

Verified locally: prettier, eslint, lint:package-json, tsc build (strict, incl. noImplicitReturns) and the jest suite all pass. Storybook stories added (Decentraland UI/Carousel): default, autoplay-disabled, narrow slides.

[cloudflare-workers-and-pages]

Deploying ui2 with    Cloudflare Pages

Latest commit:	db12f75
Status:	✅  Deploy successful!
Preview URL:	https://c0346500.ui2-423.pages.dev
Branch Preview URL:	https://feat-carousel-component.ui2-423.pages.dev

View logs