fix(reflectors): retain current peers when no candidates respond

Restore the pre-probe selection when evaluation finds no usable candidates. Preserve master’s existing selection of smaller candidate sets.

src/reflector_selector.rs

@@ -167,6 +167,7 @@ impl ReflectorSelector {
 
             let mut next_peers: Vec<IpAddr> = Vec::new();
             let mut reflectors_peers = self.reflector_peers_lock.write_anyhow()?;
+            let current_peers = reflectors_peers.clone();
 
             // Include all current peers
             for reflector in reflectors_peers.iter() {
@@ -236,6 +237,13 @@ impl ReflectorSelector {
                 candidates.swap(i, j);
             }
 
+            if candidates.is_empty() {
+                info!("No usable reflectors, retaining current set");
+                self.reflector_tx.send(current_peers.clone())?;
+                *reflectors_peers = current_peers;
+                continue;
+            }
+
             if (candidates.len() as u8) < num_reflectors {
                 num_reflectors = candidates.len() as u8;
             }