What goes in
A brand, a topic, and a BookContract — the promise the finished book has to keep (audience, register, structural shape).
Bestseller-grade books from contract and planning through composition and EPUB, across 39 brands and 14 locales.
Every book runs the same seven-stage chain — this is the Production Lifecycle (Intent → Publish) with Books' own names on each stage.
A brand, a topic, and a BookContract — the promise the finished book has to keep (audience, register, structural shape).
Structural gates, the four-piece production chord (spine + production quality + exercise journeys), and — for flagship claims — a Layer-3 line-edit pass.
A byte-verified EPUB, registered in the brand catalog, with cover art and evidence attached.
artifacts/qa/LAYER4_10CELL_BLIND_READ_PREP_2026-07-10/LAYER4_VERDICT_2026-08-09.md
Gate PASS is at most code-wired — see the Quality and Evidence Model for what "PROVEN-AT-BAR" actually requires.