pub async fn check_webhook_health(port: u16) -> (bool, Option<String>)Expand description
Check if the webhook server is healthy by pinging its local health endpoint.
This only verifies the local HTTP listener is running. It does NOT verify that GitHub can reach the endpoint (NAT/firewall) or that the webhook secret is valid.
Returns (healthy, failure_reason). failure_reason is Some when
unhealthy and cleared (i.e. None) when the check succeeds.
Logs dedup store metrics (seen_count, duplicate_count) at debug level for observability.