arch-diagram
Use when the user wants evidence-grounded Mermaid architecture or UML diagrams for a codebase or system, including context, container, component, code, sequence, state-machine, or deployment diagrams. Trigger on “画架构图”, “画 C4 图”, “生成时序图”, “状态机图”, “部署图”, “组件依赖图”, “diagram this codebase”, or “draw a sequence or deployment diagram”. Follow the fact-first flow: define scope, acquire L0–L3 source evidence, select high-value diagram types, draft Mermaid, then validate and repair. Every node and edge must trace to file and line evidence; never fabricate architecture. Output Mermaid source in text fences with Name and Slug metadata. Do not use for learning materials or generic prose explanations.
