nx_library_search_gate.nx

nx_library_search_gate.nx -- REPRODUCIBLE proof of S-class ranked retrieval over the REAL on-disk Nishi library (knowledge/library/*.txt), with NO live server (the old nx_library_search_test needs an orphaned :8099 fixture -> 0/8 when it is down = not reproducible by our system). This gate reads five real ingested docs straight off disk, builds the corpus, and asserts both rankers (ls_best TF-IDF + ls_best_bm25, the production BM25) pick the right doc for distinctive query terms, and resolve an AMBIGUOUS term (in >=2 docs) to one deterministic best -- the honest exceed over naive substring scan, which can only say present/absent and cannot rank or pick. Term doc-frequencies were verified against the live corpus before wiring. Fully sovereign + reproducible: reads local files, our own ranker, no socket. GREEN iff 8/8. license_tier: ORIGINAL