the matrix's multi-repo corpus check needs a validation corpus; disembark says the corpus manifest is not yet in the tree

the matrix's multi-repo corpus check needs a validation corpus; disembark says the corpus manifest is not yet in the tree

A sequencing impossibility (severity minor) found by the cross-document consistency pass.

• End A: .abcd/development/brief/04-surfaces/02-disembark.md:216 — "The corpus manifest (.abcd/corpus.json) is not yet in the tree."
• End B: .abcd/development/brief/06-delivery/02-verification-matrix.md:45 — "Every milestone acceptance gate passes on each corpus repo, with documented exemptions"

02-verification-matrix carries an unstaged row requiring every acceptance gate to pass on each corpus repo with documented exemptions. 02-disembark says acceptance is checked across a validation corpus but that the corpus manifest (.abcd/corpus.json) is not yet in the tree. The matrix's check depends on a corpus definition the surface chapter says does not exist, so it cannot be run as written.

Evidence: .abcd/work/reviews/2026-10-26-consistency/00-summary.md, finding 317.