diagram

# Diagram Use this skill when the user wants a rendered static diagram, a validated diagram source artifact, or a revision to an existing diagram source. Default to Mermaid unless the user asks for another format or the shape is a better fit for another adapter: - Mermaid: sequence, flowchart, state, ER, class, gantt, git-graph, mindmap, and pie diagrams. - PlantUML: UML sequence/component/activity/deployment diagrams when the user already uses PlantUML or asks for it. - Graphviz DOT: topology, dependency graphs, and layouts where rank/direction control matters. - Excalidraw JSON: hand-drawn-style editable sketches when the user asks for an editable canvas. ## Tool Surface Use the runtime tools directly: - `diagram_create`: create source, validate it, save source, and optionally render. - `diagram_update`: update existing source or source artifact, validate it, save a new source artifact, and optionally render. - `diagram_validate`: validate source only; do not render. The tool output includes these fields: ```json { "success": true, "valid": true, "source": "...", "source_artifact_ref": "/workspace/.generated-diagrams/skills/diagram/diagram-...", "rendered_artifact_ref": "/workspace/.generated-diagrams/skills/diagram/diagram-...", "type": "flowchart", "format": "mermaid", "artifacts": [], "runtime_events": [], "warnings": [] } ``` On validation failure, `success` and `valid` are false and `errors` plus `suggested_fix` may be present. When `render...