New endpoints added for managing outbound message queues: POST /v1/integrations/{integrationId}/outbound/messages/poll, .../ack, and .../unblock, plus GET /v1/integrations/{integrationId}/outbound/messages/dlq and POST .../outbound/messages/dlq/redrive for dead-letter handling
Outbound use case delivery configuration was restructured into a discriminated union of WebhookDeliveryConfig and the new PollDeliveryConfig; the previous flat type, webhook_id, webhook_name, and webhook_url delivery fields were removed (breaking)