Backend to ask.
Optionalrequested: string
The requested name; omitted for the model the CLI runs without one.
fresh asks the CLI again (doctor); probe reuses pre-probed evidence; context supplies read budget/signal.
The model, or undefined when the adapter cannot observe one or the CLI did not say.
Returns the concrete model the CLI reports for a requested name, or for no name: from memory for up to five minutes, else from
models.jsonfor up to a day, else asked from the CLI (observeModel) and recorded in both. Concurrent misses share one request.