Function detect_model_name 

pub fn detect_model_name() -> String

Return the model name to display in the status bar.

Delegates to Config::from_env() so the TUI shows the same model the runtime will actually use — including the provider.preset chain added for the preset-config goal. Without this, a user with provider.preset = "deepseek" would see “claude-sonnet-4-6” in the status bar while the agent talked to DeepSeek.