Function validate_model_selection 

pub fn validate_model_selection(
    provider: &str,
    model: &str,
) -> Result<(), AdkError>

Available on crate feature models only.

Validate a model selection without preventing newly released or private IDs.

Unknown IDs are accepted deliberately. Known retired IDs return an error; known deprecated IDs remain usable so provider-plan exceptions and staged migrations are not broken.