#70 FTX-70: PRODUCTION_READINESS.md certification

AC-1..14 matrix with pytest node-id evidence (all 14 in scope, AC-6 real via clearance+RunFlow); per-domain UB/EV requirement evidence tables; concurrency/durability evidence; ops runbook (deploy/rollback/rotation/DLQ/circuits/backups); P3 deferral register; run transcripts. Close all tickets with evidence. Phase 9 final.