Preview Model
Submits a job that previews the fields a model would expose without persisting it.
The response contains a job ID that resolves to the list of fields the model
would expose. Poll the job until it completes to retrieve the field list. The
model is not persisted — this endpoint is useful for validating a query or
configuration before calling [`POST /api/models`](../../api-reference/models/create) to save it.
