D3 v5 Zoomable Sunburst
This zoomable sunburst visualizes the hierarchical structure of the Flare software class library, showing relative sizes of modules and submodules through nested arcs. Clicking a segment zooms into that branch, while the center circle returns to the root. Built with D3 v5, it uses `d3.hierarchy` and `d3.partition` to compute the layout, `d3.arc` for path geometry, and `d3.interpolateRainbow` for coloring. Animated transitions rely on `transition.attrTween` and `transition.tween` to smoothly update paths and labels during zoom.