Function submit_factor 

async fn submit_factor(
    client: &BusClient,
    factor_id: AuthFactorId,
    outcome: UnlockOutcome,
    profile: &TrustProfileName,
) -> Result<bool>

Submit a single factor via FactorSubmit IPC and handle the response.

Returns Ok(true) if the vault is now fully unlocked, Ok(false) if more factors are still needed (partial unlock accepted), or an error on rejection.