K8: Two contracts have provability deficit (fewer tests than obligations)

[noahgift]

Finding

pv lint contracts/ reports 2 PV-PRV-001 errors:

1. color-wcag-v1: 3 falsification tests but 4 proof obligations (deficit: 1)
2. constraints-layout-v1: 2 falsification tests but 3 proof obligations (deficit: 1)

Five-Whys

1. Why lint fails? Proof obligation count exceeds test count
2. Why fewer tests? New obligations were added without corresponding tests
3. Why mismatch? No CI gate enforces test-obligation parity
4. Why does this matter? Untested obligations may contain errors that go undetected
5. Why not caught earlier? pv lint wasn't running in CI (only in kaizen sweeps)

Fix

Add 1 falsification test to each contract to cover the untested obligations.

Found via kaizen K8 contract lint sweep.