Discriminated union identifying any source of records that can feed a list
operation. The same shape is exported as AudienceSource — they are
intentionally identical so the audience picker and the list-operations
pipeline share a vocabulary.
list: an existing MJ List, resolved via its members.
view: a User View, resolved via RunView with optional runtime params.
adhoc: an arbitrary entity + filter — no persisted view backing it.
Discriminated union identifying any source of records that can feed a list operation. The same shape is exported as
AudienceSource— they are intentionally identical so the audience picker and the list-operations pipeline share a vocabulary.list: an existing MJ List, resolved via its members.view: a User View, resolved via RunView with optional runtime params.adhoc: an arbitrary entity + filter — no persisted view backing it.