Optionalid?: stringPre-minted external customer id (cust_…). Defaults to a fresh
nanoId("cust"). It doubles as the Temporal workflowId, which is what
makes a repeated start idempotent rather than a second provisioning run.
Required with a new workspace: without it the customer has no Owner.
Optionalowner?: OnboardingOwnerA reused workspace already has its owner as a member.
Everything the caller supplies to start onboarding. The customer's external id is minted here rather than by the caller, so
idis optional (supply it only to pin the workflow id — used by tests).