Face part I
A simple smiling face rendered as an SVG using React and D3. The code draws a yellow circle for the head with a black stroke, two black circles for the eyes, and a mouth created with the `d3.arc` function using a specified start and end angle. All shapes are positioned via computed center coordinates, with the face’s radius accounting for stroke width. The example demonstrates combining React’s declarative JSX with D3’s geometry helpers for static vector graphics.