Function tlsroute_arecord_cr_name 

pub fn tlsroute_arecord_cr_name(
    cluster: &str,
    namespace: &str,
    route_name: &str,
    hostname_index: usize,
) -> String

Derives the ARecord CR name for a TLSRoute.

Format: scout-{cluster}-{namespace}-{route_name}-{hostname_index}

One ARecord per hostname in spec.hostnames[]. Index tracks which hostname this ARecord is for. Applies the same sanitisation and 253-char truncation.