Fix of an missing parethasys

Web/app.py

@@ -3787,6 +3787,7 @@ def api_item_detail(item_id):
         <h2>{html.escape(str(item.get('Name', 'Untitled')))}</h2>
         <p><strong>ISBN:</strong> {html.escape(str(item.get('ISBN', item.get('Code4', '-'))))}</p>
         <p><strong>Anzahl:</strong> {html.escape(str(item.get('SeriesCount', '-')))}</p>
+        <p><strong>Code:</strong> {html.escape(str(item.get('Code_4', '-')))}</p>
         <p><strong>Ort:</strong> {html.escape(str(item.get('Ort', '-')))}</p>
         <p><strong>Typ:</strong> {html.escape(str(item.get('ItemType', '-')))}</p>
         <p><strong>Kategorie:</strong> {html.escape(str(item.get('library_category', '-')))}</p>

Web/templates/library_table.html

@@ -800,7 +800,7 @@
             return `
         <tr>
             <td class="table-title">${escapeHtml(item.Name || 'Untitled')}</td>
-            <td>${escapeHtml(item.ISBN || item.Code_4 || item.Code4 || '-')}</td>
+            <td>${escapeHtml(item.Code_4 || item.Code4 || '-')}</td>
             <td>${getItemTypeLabel(item.ItemType || 'book')}</td>
             <td style="font-weight:600; text-align:center;">${item.Quantity || item.GroupedDisplayCount || 1}</td>
             <td>