createTarget
Allocates one target set after its lifetime permit has already been reserved.
Return
a new exclusively owned target with the requested extent.
Parameters
physicalSize
positive physical pixel extent, validated with checked arithmetic by the caller.
depth
whether to allocate a depth attachment alongside color.
Throws
when rollback has not acknowledged physical destruction, transferring the incomplete target and reserved permit, including an accepted asynchronous release request.
when allocation fails without remaining native storage or pending uses of partially allocated resources.