Module dispatch 

WebSocket message dispatch for the Polymarket execution client.

Routes user-channel WS messages (order updates and trades) for orders submitted through this client into Nautilus order events (OrderAccepted / OrderFilled / OrderFillVoided / OrderCanceled / OrderRejected / OrderExpired), building them from the context captured at submit (OrderContextRegistry). Order-channel messages drive lifecycle events; trade-channel messages drive fills, and acceptance is synthesized before a fill or cancel that races ahead. Messages are emitted once the order is known (accepted, or with a submit in flight), otherwise buffered until acceptance. Reports are reserved for the generate_* query and reconciliation methods.

Trade evidence is admitted through the shared settlement boundary and governed by the settlement registry: provisional and confirmed stream statuses apply legs once per uninterrupted session, failed or conflicting stream evidence quarantines the trade for targeted terminal REST resolution, and only a REST-established FAILED outcome voids applied fills or tombstones absent legs.

Execution-client and dispatch replacement confirmations share one promotion under the dispatch lock. Execution-client confirmation uses logical-order context and local event time. Dispatch confirmation uses old-leg context and stream or REST evidence time, with local time as fallback for invalid order-update timestamps. Promotion publishes OrderUpdated before registering and releasing fills.

Execution-client confirmation drains the returned activity immediately; dispatch handlers retain their own emission order. Execution-client confirmation sets drained fill ts_init at emission; dispatch preserves buffered ts_init.