okhp3-mermaid-update

Style-preserving update of an existing Mermaid diagram. Use when the user provides an existing .mmd file (or fenced Mermaid block) and a change request - new nodes, revised labels, added edges, restructured flow, or changed content - and the goal is to apply the minimum diff required without touching the diagram's style configuration, classDef declarations, or init block. Load okhp3-mermaid-core first for audience/type context. Do NOT use this skill for syntax repair (broken parse) - use okhp3-mermaid-repair for that.