[JoyboyBrian]

The fixed-original-owner obstruction in #4751 leaves a changed original-owner query as a concrete continuation. This package changes the second paid pencil from P+2Q to P+Q and constructs an exact free decoder with zero fresh-owner contamination. It yields a pure partial A_f K_f x channel after the retained five-call preparation.

The finite word certificate keeps central phases and proves the identity at every positive tensor width. Its exact trace-power formula is

||A_f||²_HS = 8^f+(-8)^f-20(2^f+(-2)^f)+32(1+(-1)^f).

Consequently the channel is nonzero precisely at positive even widths. Its rank is one at width two. Every emitted free monomial is certified as an affine address permutation with linear/even-quadratic phase, so the constructive result uses the actual free alphabet rather than the predecessor's enlarged obstruction alphabet.

Original x,y, the fresh projector's whole complement, and dirty intermediates remain retained. This is a partial linear identity, not a full Kx,Ky unit or admission under an invertible-pencil/full-rank preparation contract. Physical preparation, routing/storage, missing target coordinates, complement recovery, terminal frames, cleanup and recursive supplier costs remain open. No new κ, selected-frontier change or paid saving is claimed.

Canonical investigation: #1166 (reply in thread) . Exact predecessor sources and changed premise are pinned in SOURCES.json and TASK.json. Credit Yiyang's phase-prefix repair and continuation, lee-phys's two-image prefix, Jacob Sussman's small-unit model and the retained source lineage. Prepared by JoyboyBrian with substantial OpenAI Codex assistance, including a separate agent's proof/code review.

Validation:

• Registered Python 3.12 normal and -O exact replay: PASS, including six negative controls, both projectors, actual free-alphabet decompositions and the complete 65,536-pair norm certificate.
• Metadata/source pins and committed bytes with source-history ancestry: PASS.
• Deterministic committed export and isolated normal/-O cold replay: PASS.
• Independent agent review and root mathematical review found no blocker; they do not constitute proof-kernel or independent human acceptance.

Hosted CI and full physical/supplier validation are not established by these local checks. The README and TASK metadata give the remaining research questions and complete unpriced obligation ledger.

Final submission checkpoint: canonical main was refreshed at 2026-10-22 20:02 UTC and remains 624de9dc66858af0945e5f8a0942488d62280d43, with guidance and dependencies unchanged. The completed 19:59 overlap snapshot covers 316 open PRs and 3,732 Discussion records; the final resonant/owner scoped search includes all 6,319 base local notes plus this package and identifies only this investigation. This is bounded coverage, not a novelty certificate.