This example demonstrates a minimal React application that renders a static SVG visualization. It displays a single blue circle positioned at the center of a 200x200 pixel SVG canvas, accompanied by a simple "Working Test" heading. The code imports React and defines an `App` component that returns the SVG markup directly using JSX. It uses the React 19 and D3 v7 libraries via an import map, with rendering handled through React's declarative component structure rather than direct D3 API calls.