* Simplify LoadingSpinner around a children loading API * Rename loading prop to isLoading for consistency across components * Refactor LoadingSpinner to use slotted recipe architecture * Add VisuallyHidden component * Switch from render to elementType * Use WCAG clip technique for visually-hidden styles Replace clip-path: circle(0) with the WCAG-standard clip technique (1px clipped box, overflow hidden, white-space nowrap) in both the visuallyHidden recipe and Text's isVisuallyHidden variant. circle(0) left a full-size layout box (overflow risk) and has questionable Safari focus-ring support. * Share visually-hidden style between recipe and Text variant