test harness: strip compare-at price in budget grader; add set-ref coref/basket/buyable blocks

coref: make the set-reference/projection class language-agnostic (Roman-Urdu)

coref: structurally resolve the prior-result-set follow-up CLASS

coref: fix follow-up cascade exposed by Codex independent 100Q (6 fails)

chore: router_ab harness — summary JSON dump + retry trim

feat: universal category resolution via the store's own collection vocabulary

feat: ROUTER_MODEL override for the multilingual catalog router (A/B plumbing)