This turn's own user; null for a turn that names none.
This turn's own namespace: on the full runtime the turn's resolved organization id, '' when it has none; on
gmi(), whose turns carry no organization, ''. Every turn is read against the namespace the session was opened
under.
The user's text; null for a tool continuation or a turn whose input is not plain text.
The models the turn may run on, primary first; empty when the caller resolves none before the turn.
True for a turn that carries metadata.workflowId.
Optional continuationTrue for a tool continuation: it belongs to the turn it continues and is never read as another user's turn.
What a GMI, or a product's own turn loop, tells its learner session before a turn.