Add fail-closed production-readiness evidence foundation

[thomaswillner]

What this changes

Publishes the first materially improved experimental LLM Errata baseline without claiming production readiness.

• Integrates the complete internal Phase 2 schemas, vectors, semantic probes, checkpoints, adapter contract, and conformance validator.
• Incorporates conflict-disclosed contributor findings with explicit attribution and without copying or vendoring external fixtures.
• Separates experimental release readiness from production readiness: G1 remains PASS; G2–G6 remain BLOCKED; overall verdict remains NOT_PROD_READY.
• Records G2–G6 as ongoing development and validation work rather than requiring indefinite waiting for unsolicited reviewers.
• Replaces an impossible sole-owner CODEOWNER approval rule with green exact-head CI, force-push/deletion protection, and public review history. Independent review remains welcomed and becomes evidence only when it actually exists.

Current evidence

• Head: 9ce456563a2a2f01358202fbe88ed9d9a4f9de91
• Exact-head CI: https://github.com/thomaswillner/llm-errata/actions/runs/31757535469
• Python 3.11: pass
• Python 3.13: pass
• Local make check: 25 repository checks, 25 claim guards, readiness/publication validation, 363 tests, expected PARTIAL demo behavior
• git diff --check: clean
• Canonical G2 surface digest remains 3ca427bb2645517e1b1d921859a7721896644a05e32ea39fb0071a021ddc5b6d; release-policy-only changes do not alter the conformance surface

Release boundary

Version 0.4.0 is an experimental conformance proposal and tested reference implementation. It is useful for public evaluation and further development. It is not a production protocol, certification, security audit, or proof of interoperability.

Open work remains:

• G2: qualifying independent conformance review, if and when a reviewer engages.
• G3: audited constant-time production cryptography and lifecycle review.
• G4: two independently established adapters and a separately produced validator.
• G5: experiments across three independently operated real memory systems.
• G6: measured operational security, observability, recovery, compatibility, and performance evidence.

Ownership and licence

Repository-authored work remains copyright Thomas Rainer Willner. Rastislav Drahoš/DanceNitra retains copyright in the external candidate fixture and receives explicit contributor credit. Independent commercial and non-commercial specification implementations are permitted under the attributed implementation grant. Reference Code remains personal-use restricted. No endorsement, certification, partnership, exclusivity, patent grant, or transfer of contributor copyright is implied.

Checks

• make check passes locally
• Exact-head GitHub Actions pass
• Quarantine still precedes repair
• Correction, supersession, and erasure remain distinct
• Repair triad remains negative, positive, preservation
• Unknown, partial, or failed coverage cannot become aggregate success
• Erasure evidence remains content-free
• Novelty wording remains bounded and dated

Removals

No technical qualification, prior-art record, contributor attribution, readiness gap, or security boundary is removed. Only the unavailable-reviewer publication deadlock is retired.