Marks the submission pending and queues the 3PL adapters' fulfillment-order-created message (delayed export bypassed), published after the commit. Refused (409) when the fulfillment order or its order is held, not pending, not open, hidden from the shipping queue, EDI-routed or not adapter-routed.
Scope: fulfillment:write, channel:write or admin. A permission group made before the Channel API scopes existed grants it as fulfillment-orders:manage.
Idempotency: send Idempotency-Key; a retry with the same key replays the first answer.
Rate limit: write class, 1,200 requests per minute per tenant by default (read class 6,000). Every response carries X-RateLimit-Limit, X-RateLimit-Remaining and X-RateLimit-Reset; a refusal is 429 rate_limited with Retry-After.
