core/comprehension_attempt/failure_family.py: partitions every reachable organ refusal reason (R1 reader/admissibility, R2 reader/solver/answer-choice) into a named FailureFamily declaring owner / must_remain_refused / proposal_allowed / safe_next_action / proposal_target. family_for_reason is total + unambiguous (partition asserted by test); enrich_family resolves an attempt's family.
Only THREE families are growth surfaces (proposal_allowed=True): the R2 missing_category_pair / missing_total_count / missing_weighted_total gaps. All other reasons are correct wrong=0 boundaries (refuse, no proposal) — correct refusal != missing capability. answer_key_contradiction is a report verdict (no reason). Reserved R3 families forward-declared. 9 tests incl. whole-surface coverage + partition.
