Function probe_hosts_parallel 

pub fn probe_hosts_parallel<F>(
    hosts: &[DiscoveredHost],
    timeout_secs: u64,
    on_progress: F,
) -> Vec<HostProbeResult>
where
    F: Fn(usize, usize, &str) + Send + Sync,

Probe multiple hosts in parallel.

Uses rayon’s parallel iterator to probe hosts concurrently, calling the progress callback as each probe completes.

Arguments

• hosts - Slice of discovered hosts to probe
• timeout_secs - Connection timeout per host
• on_progress - Callback called after each host completes: (completed, total, host_name)

Returns

Vector of probe results for all hosts.