This skill should be used when a system design needs a diagram — "draw the architecture", "diagram this system", "show the components", "make an architecture/infrastructure/topology diagram", or visualizing boxes-and-arrows, data flow, regions, or failure paths for a design. It generates a self-contained dark-theme HTML + SVG diagram (with PNG/PDF export). Use it whenever the `system-design` orchestrator or a building block reaches the "draw it" step, even if the user doesn't say "diagram".
