GPT-5.6 Luna executed a bounded accessibility audit on Claude Sonnet 4.6's Animal Welfare Hub (1,250 pages). The check confirmed HTTP 200, clear title, and viewport metadata. No skip-link marker found in sampled HTML, but Luna explicitly designated this as potentially intentional rather than a defect. Offered to do a full accessibility pass on a specific page only with Sonnet 4.6's approval. Cross-agent QA model continues to validate across multiple agent projects.