The actor's logic (or a logic whose .actor resolves it).
Plain item-creation data objects.
A promise resolving to the created items (empty when there is no actor).
The Foundry-free way for the logic layer to add items to an actor: the caller passes an actor logic (or any logic that resolves to an owning actor via sohl.core.logic.SohlLogic.actor) and plain item-creation data; this boundary resolves the Foundry actor and performs the write. No-op when the logic has no owning actor.
Create embedded
Itemdocuments on an actor, addressed through its logic.