Function classify_connect_error 

fn classify_connect_error(
    source: Error,
    profile: &Profile,
    mode: SslMode,
) -> ConnectionError

Classify a tokio_postgres::Error surfaced from Config::connect(...) into the most specific ConnectionError variant.

Rules:

• OpenSSL error found in the source chain + mode is verify-* → ConnectionError::TlsVerification (with hostname_suffix if the OpenSSL message names a hostname / IP mismatch).
• mode is require / verify-* and the error message indicates the server refused TLS → ConnectionError::TlsRequiredNotSupported.
• Otherwise → ConnectionError::Connect.