nx_ltr_lib_gate.nx

nx_ltr_lib_gate.nx -- teeth for the learning-to-rank reranker (nx_ltr_lib.ltr_cv) on a synthetic fixture it builds itself (search rung R0, 2026-09-14). A SIGNAL fixture where one feature predicts the sparse relevant candidates -- the trained arm's 5-fold held-out nDCG must be high; a SHUFFLE neg-control where gold is decorrelated from every feature -- with 20 candidates and only 3 relevant a random ordering pushes them out of the top-10, so it must score LOW (the model may not hallucinate signal); determinism (integer, so the same fixture twice is the same number). No corpus, no fork. Declared in organ_gate.conf.