fix: route peer allocation through selected network

crates/nx9-wg-api/tests/test_ui_endpoints.rs

@@ -123,6 +123,16 @@ async fn test_ui_spa_index_and_stylesheet_endpoints() {
     assert!(html.contains("triggerCreateBackup"));
     assert!(html.contains("openClientExportModal"));
     assert!(html.contains("openAddPeerModal"));
+
+    // Peer enrollment must submit the selected Network UUID as network_id,
+    // never the display name or CIDR.
+    assert!(html.contains(r#"value="${n.id}""#));
+    assert!(html.contains("${escapeHtml(n.name)} (${n.cidr})"));
+    assert!(html.contains("network_id: networkId"));
+    assert!(html.contains("isNetworkUuid"));
+    assert!(html.contains("selectedNetwork.id"));
+    assert!(!html.contains("network: network || null"));
+    assert!(!html.contains(r#"value="${n.name}""#));
 }
 
 #[tokio::test]