Social Network Graph Example
A social network graph example visualizes five people (John, Alice, Bob, Eve, Cynthia) as blue circles connected by six friendship links as lines. Using D3 v6, the code employs `d3.forceSimulation` with `d3.forceLink`, `d3.forceManyBody`, and `d3.forceCenter` to position nodes, while `d3.drag` enables interactive dragging. The SVG rendering updates node positions (`cx`, `cy`) and link coordinates on each simulation tick, with text labels showing names. This demonstrates loading D3 via UNPKG and importing local ES6 modules.