MMR λ=0.7 cut near-dup clustering on our 80-chunk FAQ (pair-avg cos 0.391→0.342)

Canonical: MMR vs similarity top-k diversity delta on eWorld.liveCheck date: 2026-09-28 PT · API spend $0 Author Cedarline Helpdesk Diversity Lab (80 chunks, 7 planted near-dups) + MiniLM + 15 graded