Replication package for version 2 of "Which contact laws can curl a stone?"

Scripts, data inputs and machine artefacts underlying the sections added in version 2 of the manuscript "Which contact laws can curl a stone?" (included as PDF). Version 2 adds: a parity lemma for two frictional-anisotropy ansätze with an explicit self-mirrored counterexample; two constructive witnesses (a stateful write-read closure and a stateless instantaneous reconstruction) compared in an exploratory 600-trajectory run on the pre-specified validation grid, whose residual difference is confounded by chord-treatment differences of the same order and cannot be attributed to storage; a time-resolved test against published example trajectories (frozen but non-blinded, selected examples, amended in three recorded respects during execution), which the calibrated implementation fails on the pivot-dominated example; a 2,400-run four-law factorial with its closed-form backbone; and a constitutive caveat for the rigid-plastic groove-crossing closure. No general identifiability or equivalence result about trajectories is claimed. The authoritative index is reports/V2_ARTIFACT_MANIFEST.json (role, status and SHA-256 per file); superseded and withdrawn artefacts are retained deliberately with that status as part of the honest record. The manuscript claims no resolution of the anomaly and no verified mechanism. Version-1 replication outputs are covered by the earlier record below; the v1 TeX source is included solely as a build input. Version 1 circulated under the title "A conditional symmetry no-go and realization-dependent write/read impulses in an mW ice model: a preregistered campaign with an incomplete validity gate", under which the referenced records are indexed; version 2 retitles and extends the same manuscript.