[PradipNichite]

This retrospective connects the published S64 unsupported-data failure to the already released DA-001 correction. It adds one complete case study, a prominent README entry, index/history links, and the corresponding source-manifest hashes.

The original result remains Fail; the engineering correction is released; an independently accepted S64 benchmark retest remains pending. The case explains the chronology explicitly: September evidence, engineering recorded20October, and public finding published21October2026. The fix predates this public repository; this is a new documentation PR, not a historical implementation PR.

The document links the current public strict-Boolean answerability contract, SQL/execution/final-answer/cross-database paths, existing mocked regression controls, the synthetic fixture, and the previously approved summary of independent engineering validation. It retains the unknown original hosted build/model and does not claim a universal semantic-support guarantee.

Validation: published resultHTTP200 and source/code inspection; changed-document relative links checked; manifest hashes generated from actual staged Git blobs. Backend, frontend, tests, deployment/workflow files and all17published-result records are unchanged. No historical product controls, model requests or benchmark evaluation were rerun for this documentation.

• Published original finding
• Retrospective at the reviewed commit

Merge follows independent documentation/claim/link review and the repository's applicable checks. No S43 work or new feature issue is included.