refa: improve tree clustering (#17285)

web/src/components/ui/tree-view.tsx

@@ -142,7 +142,7 @@ const TreeItem = React.forwardRef<HTMLDivElement, TreeItemProps>(
         <ul>
           {data.map((item) => (
             <li key={item.id}>
-              {item.children ? (
+              {item.children && item.children.length > 0 ? (
                 <TreeNode
                   item={item}
                   selectedItemId={selectedItemId}

web/src/pages/chunk/representation/utils/adapters.ts

@@ -48,6 +48,11 @@ function buildTreeDataItems(
 
   for (const relation of relations) {
     if (!relationTypes.includes(relation.type ?? '')) continue;
+    // Self-referencing relation (same entity as its own child) creates
+    // an infinite recursion in the tree renderer.  This is a backend
+    // data integrity issue (duplicate entity names) but we defend
+    // against it in the frontend so the UI never hangs.
+    if (relation.from === relation.to) continue;
 
     const parent = map.get(relation.from);
     const child = map.get(relation.to);