Function resolve_model_provider_type 

pub fn resolve_model_provider_type(
    type_key: &str,
) -> Option<(&'static str, bool)>

Resolve a Quickstart provider-type input to the canonical config family.

The provider registry remains the source of truth for real config families. Auth-provider aliases (openai-codex, claude, google, grok, …) are accepted as Quickstart conveniences and normalize to existing config families. Only openai-codex preselects a different Quickstart auth mode.