Add Iroh peer ping

crates/geth-discovery/src/lib.rs

@@ -107,6 +107,8 @@ struct PeerCardSigningPayload {
 pub struct EndpointCandidate {
     pub endpoint_id: String,
     pub relay_url: Option<String>,
+    #[serde(default)]
+    pub direct_addresses: Vec<String>,
     pub source: DiscoverySource,
 }
 
@@ -198,6 +200,7 @@ mod tests {
             vec![EndpointCandidate {
                 endpoint_id: "endpoint:iroh".to_owned(),
                 relay_url: None,
+                direct_addresses: vec!["127.0.0.1:12345".to_owned()],
                 source: DiscoverySource::Manual,
             }],
             UnixMillis(1),