Verifies the V-Model artifact graph is intact: BA sections, Epics, Features, Success Criteria, ADRs, arc42 sections, PLANs, Backlog, Wayfinder rows, and code references. Two modes: syntactic (links, IDs, Refs) and semantic (content coherence via an agent). Default syntactic at the end of every skill phase. Semantic before release or on explicit request. Use this skill when the user mentions "consistency check", "graph check", "check references", "dead links", "orphan features", "graph-health", or when another V-Model skill completes a phase and wants to verify the artifact graph before handoff.