Invariant 8 puts an Acceptance block on every 'brief phase'; the mental model puts it on the press release and surface chapters, with phases retired

Invariant 8 puts an Acceptance block on every 'brief phase'; the mental model puts it on the press release and surface chapters, with phases retired

A terminology drift (severity minor) found by the cross-document consistency pass.

• End A: .abcd/development/brief/02-constraints/03-invariants.md:153 — "Every brief phase has an ## Acceptance block in the same format."
• End B: .abcd/development/brief/01-product/03-mental-model.md:85 — "The brief's press release and surface chapters carry an ## Acceptance block in the same format."

Invariant 8 says every brief phase has an ## Acceptance block. The mental model says the brief's press release and surface chapters carry that block, and states that the phase is retired. The invariant uses a retired unit for the home of brief-level acceptance, so the invariant and the model name different homes.

Evidence: .abcd/work/reviews/2026-10-26-consistency/00-summary.md, finding 16.