Certify the global six-source DUO batch optimum (140 queries, 142 adds)

[Tairitsu-Aya]

PR2128 supplies a six-source DUO batch with 140 root queries and 142 source/readout adds. This package proves that it simultaneously minimizes both charges in the inherited single-dirty-connector model, including schedules that use more than two readouts for some outputs. The abstract query/add frontier is the single point (140,142); the attaining construction remains credited to Aaron Wang/Navinor.

The key unrestricted basis value is known: Volodymyr Gavrylkiv, JIS 20 (2017), Table 3, reports r[(C2)^6]=14. This package independently rebuilds its finite lower bound and applies it to the complete connector bill. A full-cover 13-point set can be translated and linearly normalized to contain zero and the six coordinate vectors. Two code-disjoint enumerators exhaust all 36,288,252 remaining combinations and agree on the complete histogram: maximum 63/64. Thus paired universality needs at least 14 source calls at every add budget. The README also bounds schedules with missing masks and extra readouts, and uses the replayed 12/14-add singleton controls to establish the separate 142-add floor.

The original (13,16) handoff is retained as a separate restricted cross-check: two other enumerators agree byte-for-byte on all 7,480 full-cover expansions among 54,864,810 normalized words; a literal Python audit checks all 86,900 legal hidden triples over 251 complete rotation/reversal orbits, with maximum 63/64. This cross-check is not presented as a new group-theoretic lower bound.

Validation:

• Full four-census Python3.12.3/Ubuntu24.04 replay, including C++17 compilation: PASS, initially 13.31 seconds and 120,300 KiB peak RSS on one CPU. g++13.3.0 with warnings as errors; no dependency download.
• Both unrestricted enumerators pass complete UBSan runs. The verifier checks 256 affine normalization controls, retained 14-point and small DUO positives, full dirty-input replay over 70/140/210 independent columns, four behavioral mutations and three deadline-truncation rejections.
• Ten isolated source-export/boundary checks, Windows3.12.9 optimized portable restricted audit, metadata/source pins and whitespace checks pass. The Windows portable audit does not establish either complete native census; full native Windows replay was unavailable.

python3.12 scripts/research_package.py --package research/six-source-duo-add16-floor

Only the new scoped package is added. Scientific base is canonical main 0fdd7d82de03e43c9e5a1000dfbcd380d1b687d2, priority revision 4. Exact sources, changed assignment, literature credit, validation and remaining physical-admission question are recorded. Canonical investigation.

Credit Ross Richardson for the interface/prefix reduction, Navinor for DUO, Aaron Wang/Navinor for PR2128's witness, Douglas Colkitt/Hanson Sun for the singleton census, and Volodymyr Gavrylkiv for the unrestricted basis value. Substantial OpenAI Codex assistance for Tairitsu-Aya in mathematics, code, verification and writing; all independent algorithms have the same author/assistant, with no independent human or formal-kernel review claimed. Apache-2.0. Physical supplier, compiler, frame/owner, hosting, precision/tape and all-size obligations remain. No selected-frontier or kappa change.