move resequenceFrame, heap dupe, and broadcast_queue.push() outside the ordering lock. persist_order now covers only the DB persist call and seq store — the minimum needed for monotonic sequence assignment. this eliminates the cascade where producers spin on persist_order while another producer is blocked in a full broadcast_queue.push(). slight out-of-order in the ring is acceptable — seq is embedded in frame data and consumers/history track by seq. metrics showed persist_order_spins_total dominating at ~1,100 hosts (548M spins) while push_lock_spins was zero — confirming the critical section width was the bottleneck. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>