design-doc-mermaid@r1

Publisher claims: "Create Mermaid diagrams (flowchart, sequence, class, ER, state, C4, architecture) from text or source code. Default for GitHub wiki. Use when asked to create a diagram, generate mermaid, document architecture, or convert code to diagram. PlantUML is only for leftover types. Confluence needs PNG/SVG as well as the fence." Observed in sandbox: no network, touches nothing outside the project, writes no memory.