Function derive_onboard_status 

pub fn derive_onboard_status(cfg: &Config) -> OnboardStatusResponse

Pure derivation of the onboard-status response from a config snapshot. needs_onboarding is false iff at least one enabled [agents.<alias>] block has a resolved model provider with a selected model plus resolved risk/runtime profile refs. A provider without a bound, runnable agent is not a completion signal: chat dispatch still bounces with a setup error in that state.