nx_tptp_load.nx

nx_tptp_load.nx -- end-to-end TPTP CNF file loader. Per user directive 2026-05-15: all functionality native to NishiLang, no shell preprocessing or Python. Reads a TPTP file via the native sys_read_file primitive, walks the buffer parsing each cnf(name, role, FORMULA). statement, returns an array of *Clause ready for the saturation loop. Phase 1.6 closure: this is what flips the vs-Vampire CASC bench status from BLOCKED_ON_TPTP_FORMULA_PARSER to UNBLOCKED_FOR_CNF. (FOF formulas still queued for Phase 2; CASC FOF division entries must be CNF-converted before the substrate can solve them today.) Result-typed throughout (per cardinal: no null-as-error sentinels). Caller unwraps via nx_result_unwrap; on error inspects err_code (NX_ERR_FILE_NOT_FOUND / NX_ERR_PARSE_FAILED / NX_ERR_OVERFLOW).