Smiley Face Part III
A smiling face rendered with React and D3 draws its features using SVG shapes and a custom stubble pattern. The face includes yellow circular head, black-outlined eyes, a mouth arc, and a grey stubble region defined by a pattern of small circles clipped within a polygon. React manages the component structure while D3’s `arc` generates the mouth path. The code uses explicit coordinate math for layout and applies the pattern via a clipPath.