[sk1-j]

Change and mathematical scope

The standalone scripts/verify_cold617_interface.py accepts a scalar-preserving frame mutation of the archived PR626 CK provider: changing only tail[34][-1] from frame 52 to FULL makes helper 234 descend back to frame 52 at its next touch, while the script still reports PASS. Its last-touch check does not inspect the earlier frame history.

The full transport verifier already checks monotonicity. This is a standalone interface coverage gap, not a counterexample to the selected construction or a new kappa claim.

This adds one self-contained package under research/helper-frame-lifetime-audit/: an independent checker using exhaustive F2 span enumeration, a temporary-copy reproduction of the old acceptance, 17 regression tests, and source-pinned receipts/research note. Persistent helper frames are checked through A, B, tail and final climbs, with prefix and cleanup exclusions. Scalar identities, center cut excursions, wrapper identities, cost/hosting and all-size/analytic obligations remain outside this audit. Frozen sources and the selected record are unchanged.

Base: 66849e1475c930fd7732b1a0067ffee7e1e95f60. Sprint seed 28 (complex supplier), scoped to verification of that supplier. Credit to Jeremy Kothe (#622/#623 and preceding constructions), Chafik Boukhalfa (#626), DreamingOfClouds, icekylinx and the transport lineage, Douglas Colkitt, and the cumulative contributors. Prepared for sk1-j with substantial OpenAI Codex assistance. Apache-2.0.

Validation

On Windows / CPython 3.12.14:

python3 -B research/helper-frame-lifetime-audit/verify.py
python3 -B research/helper-frame-lifetime-audit/test_verify.py
python3 -O -B research/helper-frame-lifetime-audit/test_verify.py
python3 -X utf8 -B research/helper-frame-lifetime-audit/reproduce_gap.py
python3 -X utf8 -B scripts/verify_selected_result.py

Both archived providers pass: 492 helpers each, including 58 early ends, with 5,804 CK and 5,732 JP8 persistent helper touches. All 17 tests pass with and without assertions. The old interface accepts original and mutated words; the independent checker rejects the mutation at tail[35]. The selected source inventory/proof-supplement check passes; the Windows invocation used an extended-length absolute script path.

make verify and the full cold replay were not run: this environment has no make or configured Linux runtime. This draft is a scoped independent verification contribution, with no construction or bound change. The new checker/tests use only the standard library; reproducing the existing interface uses its dependencies.