legal-rag-router: Deterministic Citation Routing for UK Legal RAG, Measured Against Gemini, Jev and Laya

An open-source router that binds a legal RAG query to the cited UK provision before vector search. Blind sealed run, 29 September 2026: 0 of 1,897 real citations bound to the wrong instrument. Gemini 3.8 Flash (high) routing on its own, 1 October 2026: 102 of 1,897.