nx_engineer_wire_test.nx

nx_engineer_wire_test.nx -- the ENGINEER wires the BM25 ranker into the library search and CERTIFIES the swap before it is accepted. It runs the OLD ranker (ls_best, TF-IDF) and the NEW one (ls_best_bm25) over a labelled query set, then checks non-regression + improvement: Q1 "injury" (length-bias) ground-truth = doc0 (short focused). old TF-IDF picks doc1 (diluted, WRONG); BM25 picks doc0 (RIGHT) -> an improvement. Q2 "court" ground-truth = doc3. both rankers pick doc3 -> no regression. Verdict must be WIRED_OK (0 regressions, >=1 improvement). It also proves the gate REJECTS a regressing swap. Exit 0 on 6/6. license_tier: ORIGINAL