experiments: freeze Qwen V8 verification design

[atimics]

What changed

• Freezes the Qwen3.5-0.8B V8 installed-memory capability question, controls, acceptance gates, and bounded execution envelope.
• Records that PR 31 already contains current upstream main, so its requested rebase is a verified no-op, while preserving immutable V7 source and evidence identities.
• Adds machine-readable contract, source audit, digest, and seven static integrity tests.
• Repairs the PR 31 verification baseline across deterministic scalar decoding, SDF tolerance portability, staged splat optimization, AMP work accounting, MIS generation assertions, and duplicate-module unifier audits.

Why

V7 qualified preservation and native full-sequence C recurrence but deliberately did not test whether installed sidecar memory helps retrieval. V8 isolates that capability effect with BM25, shuffled-index, and typed-refusal controls. Formal inputs are still pending and cloud execution remains unauthorized.

The full suite also exposed platform-sensitive baseline assertions that prevented PR 31 from acting as a clean independent verification branch. The fixes preserve the underlying scientific contracts while removing BLAS, compiler, scheduler, and duplicate-basename accidents.

Impact

This is a design and verification change only. It launches no compute and does not authorize the one formal V8 attempt. A later stacked evidence PR must bind implementation and dataset identities through ilxyr admission.

Validation

• Workspace gate: pass, 1 commit, 18 files, 689 changed lines, no protected paths.
• Required suite: 6337 passed, 77 skipped, 21 warnings.
• Exact head: 43e2a2f.
• Base: codex/qwen-ilxyr-experiments.