Finite bit construction: R480 Q-node5 saves 20 ADDs (no new kappa)

[martinxxx9]

The historical PR503/510 R480 word's zero-based Q-node 5, frame 487, has a 41-XOR replacement for its original 51-XOR circuit. Paying literal reverse cleanup reduces the complete word from 33,958 to 33,938 ADDs. All twelve ordered Boolean outputs, 480 arbitrary dirty helpers, 720 register frame paths, nine COPY/ERASE pairs and paid rank mass 5,592 are preserved. Finite bit-circuit construction; no new kappa. Only research/r480-qnode5-seed05/ is added.

The exact whole-word positive invoice remains within the inherited 104-bit cap: forward bound 176,135 unchanged; reverse bound 3,751,204 → 3,714,396; payload bit length 102. Integer-transfer equality with the original is not claimed. The new independent set-valued verifier checks every dirty-input column, and the unchanged inherited xcheck, PR425 interface checker and exporter pass. Complete raw records agree byte for byte. Literal 5/9/11-stage Python scalar replays on both words cover 960/1,440/1,680 columns. 93 negative controls include all 41 single-gate omissions, endpoint-valid stale cleanup, endpoint-valid precision overflow, and all 48 candidate bridge omissions.

Reproduce with Python 3.11+ and its standard library:

python3 -I -B research/r480-qnode5-seed05/verify.py --replay-search

Expected: PASS_R480_QNODE5_SEED05 gates=51->41 ADDs=33958->33938 columns=720 payload_bits=102 controls=93 rank_mass=5592 no_new_kappa.

OS assignment seed 5, bit-supplier track; exact base abdc6a7002abdbcd9e21bfc5e1a795784deacfdf, unchanged on refresh. The search completes exactly 2,000 seeded two-sided Boolean elimination trajectories, paying every permutation repair; trial 1897 supplies the selected witness. This is a bounded heuristic, not a minimum or impossibility theorem. Source pins, exact certificates, proof, coverage histogram, local sprint claim and validation are included. Five package test groups pass, including a relocated optimized replay, source/candidate corruption controls and deterministic regeneration. Exact staged Git blobs pass in a minimal checkout. Five selected-record test groups pass, with the accepted PR942/PR589 frontier unchanged.

Overlap and credit: pending PR1003 (b0eda846c34413dabd1e75402b8ad730f8940ff2) already supplies a shorter Q-node 2 and the complete-prefix admission precedent; PR1027 (ebc027e26a7018b73a5a452eae269a9bfeaabce9) concerns quad12. Their implementations are not imported and savings are not composed. This adds a distinct object and independent finite evidence. Metadata was refreshed through #1086; no Q-node5 scope was found. Credit eumemic, DreamingOfClouds, Dylan Crow, DaysSky, Zhihao Chen and the retained E8 lineage; Jeffrey Cox's PR754 and Hao Yan's PR823 precede local resynthesis; ToikY's PR1003 is explicitly credited.

Limits: make verify was attempted once but could not start because make is unavailable in this Windows environment. Native C++ executables were not built/run; the new Python engine follows their pinned finite schedule rule. No full-suite, hosted-parent invoice, selected cold replay, supplier/outer assembly, remote CI pass, measured multiplication speedup or full multiplication-theorem formalization is claimed. Inherited all-size/compiler, realization, whole-call hosting, physical routing, precision/tape and analytic assumptions remain. upstream/ and all consumed packages are unchanged.

Prepared for @martinxxx9 with substantial OpenAI Codex assistance in mathematics, implementation, verification and writing; one AI agent, no independent human review implied. New material is Apache-2.0. Do not merge automatically or alter the selected frontier.