Sync styleguide 2026.05.18.1

docs/styleguide/styleguide.css

@@ -11,6 +11,7 @@
 @import "./styles/26-patterns-vsf-list-card.css";
 @import "./styles/27-patterns-delete-confirmation.css";
 @import "./styles/28-patterns-notifications.css";
+@import "./styles/29-patterns-left-navigation.css";
 @import "./styles/30-layouts-card-list-page.css";
 @import "./styles/33-layouts-vsf-list-detailseite.css";
 @import "./styles/34-layouts-vsf-listen-uebersicht-seite-v2.css";