DATA_PRODUCT_ACCESS_POINT_SOURCE_CODEC: NodeSpecCodec<
    DataProductAccessPointSource,
> = ...

A data product's access point (PLAN §6.8): where it is, and once resolved its schema snapshot, so inference works offline. The project, its version and the warehouse are the cube's model's. The deployment id is text, as the catalog gives it. Unresolved and failed sources have no snapshot and load unresolved: the host resolves them again.