Codex FIX7 Blueprint Recheck 6 - Readme First

Date: 2026-06-09 Mode: READ-ONLY production; KB review/checkpoint writes only.

Final status: FIX7_REFACTOR_BLUEPRINT_CODEX_RECHECK_6_NEEDS_T1_FIX

T1 fixed several recheck-5 defects correctly: full-path membership is reproducible, doc 00 full-document hash is non-authority, and the blueprint checkpoint is now report-only. Codex independently recomputed membership hash f2bda8effc7be19b54722828126b82d7d2d48bee5e5e5dc0c8f347ce210fe251.

Codex cannot seal because two root blockers remain:

1. FIX7-CANON-V1 still lacks byte-exact escaping and deterministic active-section/fence extraction for load-bearing aggregate/content hashes.
2. The detached-seal model is circular: the envelope manifest binds the Codex checkpoint content hash, while that checkpoint contains the detached seal that binds the envelope manifest; seal_report_checkpoint_content_sha256 is also self-referential.

No implementation-authoring planning or production implementation is approved.