Primitives (Base UI)

The second provider behind the ai2 primitive adapter: the same surface as @ai2/primitives, bound to Base UI instead of Radix. A pro block imports the adapter, not the library, so the same block source runs on either one. Anatomy differences are absorbed here (Base UI wraps the slider track in a Control part and calls the filled part Indicator, and it renders a native range input inside the thumb, so focus styling is mirrored from focus-visible to focus-within). Primitives with no Base UI counterpart are deliberately left out rather than silently falling back to Radix.