style(assets): add css to handle tabs wrapping in widget group headers

assets/newspaper.css

@@ -45,3 +45,10 @@
 
 /* Tighter, denser article lists — closer to print */
 .widget-type-rss .list > * { padding-block: 0.35rem; }
+
+/* Tabs wrap to the next line instead of ever showing a horizontal scrollbar */
+.widget-group-header .widget-header {
+  flex-wrap: wrap !important;
+  overflow-x: visible !important;
+  row-gap: 0.3rem;
+}