This skill should be used when the user asks to "build knowledge graph", "trace requirements", "show traceability", "map dependencies between artifacts", "visualize requirement flow", or "detect orphan nodes". It builds a knowledge graph tracing Constitution principles to requirements, tests, and tasks with edge types (governs, verified_by, implemented_by, validates). Use this skill whenever the user mentions knowledge graph, traceability, orphan detection, or requirement mapping.