Function wrap_verifier_url_error 

pub fn wrap_verifier_url_error(
    err: Error,
    verifier_url: Option<&str>,
    using_etherscan: bool,
) -> Error

Wraps a failed verification error with guidance when --verifier-url looks misconfigured for the Etherscan provider. Returns err untouched when no hint applies.

The hint only fires when the Etherscan verifier is active: it requires an API endpoint (typically /api). Sourcify, Blockscout, etc. accept host-only URLs, so we leave their errors alone.