No longer ask for API key in console, tell user to set it in env or config.
Better check message for "init-model-provider": Setup currently ignores the set "init-model-provider" anyway if, say, "Anthropic" is set but only OpenAI keys are available in the env or config. So the chat will proceed with OpenAI default even though the user may assume that they're chatting with an Anthropic-provided model. We should have some message to say that this has been ignored, at least.