fix: prevent long site title truncation in sidebar header

Override just-the-docs fixed header height to allow multi-line titles.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: emmanuelknafo

_includes/head_custom.html

@@ -11,4 +11,11 @@
 </script>
 <style>
   .mermaid { text-align: center; }
+  /* Allow long site titles to wrap instead of being clipped */
+  @media (min-width: 50rem) {
+    .site-header {
+      height: auto;
+      max-height: none;
+    }
+  }
 </style>