Releases the open reservation at the old queue and reserves it at the new warehouse queue in one transaction. An external, tenant-portal or 3PL fulfillment order takes the routing of the new warehouse (3pl with its linked adapter, else tenant-portal); a vendor fulfillment order keeps its vendor. Closed and canceled refuse (409).

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.