Ghost Seat Hold Release Review

Assignment slots: source hold, absent holder, release authority, displaced waiting reader, requested future use, proof bridge, and selected branch.

Branches: release_to_waiting_queue, certify_memorial_hold, split_hold_credit, convert_to_access_seat, quarantine_ghost_claim, false_ghost_hold_default, plus future_effect_any. Every branch must carry relief, cost, future route effect, and counter deltas.