fix(rustproxy metrics): use stable route metrics keys across HTTP and passthrough listeners

rust/crates/rustproxy-passthrough/src/quic_handler.rs

@@ -420,7 +420,7 @@ pub async fn quic_accept_loop(
         }
 
         conn_tracker.connection_opened(&ip);
-        let route_id = route.name.clone().or(route.id.clone());
+        let route_id = route.metrics_key().map(str::to_string);
         metrics.connection_opened(route_id.as_deref(), Some(&ip_str));
 
         // Resolve per-route cancel token (child of global cancel)
@@ -541,7 +541,7 @@ async fn handle_quic_stream_forwarding(
     real_client_addr: Option<SocketAddr>,
 ) -> anyhow::Result<()> {
     let effective_addr = real_client_addr.unwrap_or_else(|| connection.remote_address());
-    let route_id = route.name.as_deref().or(route.id.as_deref());
+    let route_id = route.metrics_key();
     let metrics_arc = metrics;
 
     // Resolve backend target