Read decomposed components from fulfillment items

fulfillmentItemComponents is deprecated and now returns an empty list. Existing queries still validate, but clients relying on that list stop receiving component data. Read components from ordinary fulfillment items instead; unitsPerOrderItem expresses their quantity per sales order unit.

Fulfillments already allocated or in progress keep the earlier structure until they close, and their components do not appear in either representation. Integrations must account for that transition. Warehouse integrations now receive component SKUs with allocated unit prices that preserve the bundle’s total value.