Independently corroborate coalesced P104 private reuse and boundary variants

[SHIN09-git]

This is independent corroboration of the retained-boundary composition in #2305, using a separately written rational-row/frame interpreter saved before inspecting that submission. It combines David Arias's #2152 coalesced forward word with Cinna Davis / 1337isnot1337's #2219 helper-7 reuse. The publication refresh found Gareth Davidson's concurrent result; 20 exact receipt fields agree. A separate package directory avoids a path conflict.

The full 735-input identity retains all 339 coalesced frame changes and all public boundary widths, saves nine scalar ADDs, and replaces H2 + H7 by H9. The conditional local-plus-idle invoice improves but remains 1.19328548% below selected kappa. This PR also records an original-word positive control and a released-boundary companion whose changed owner contract is explicitly unresolved. No selected frontier or supplier-admission claim changes.

Validation:

• Registered package replay passes after relocation (184.527 seconds); exact rational rows, five semantic rejection controls, native signed Pauli/global-phase checks, 4,096 Gaussian columns per variant, and 75,888 conditional placements.
• Source-only replay without optimization also passed (338.765 seconds); CPython 3.12 standard library only.
• Run: python -B scripts/research_package.py --package research/p104-coalesced-private-reuse-audit.
• Frozen native, geometry, owner and interval engines are inherited from Construct complete P104 forward word and conditional hosting invoice #2152, not independently reimplemented. Local checks are not hosted-CI results or a formal proof of the full multiplication theorem.

Pins: #2152 at 05f7aad0f08992ee48ec2dd93e896d9a4567847d; #2219 at 3f913bc17276b68f0c9008a1202b6ce588e77ff6; comparison #2305 at 335e78619a17b7c418e11306f86a72fd366de35b. Source hashes, attribution, assumptions, overlap checkpoints, exact result and reproduction commands are retained in the package. Prepared for SHIN09-git with substantial OpenAI Codex assistance; Apache-2.0.