Explicit subfolder/frontmatter wins; otherwise a classifier and an
independent scorer must agree above a threshold on a known, eligible wing.
Anything else is an Exception for a human. Never creates a wing, never
assigns an ineligible (client/untagged) wing. Mutation-checked: dropping the
eligibility, known-wing, scorer, threshold or conflict check fails a test.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>