fixup! ✨(frontend) add keyboard navigation for subdocs with focus activation

src/frontend/apps/impress/src/features/docs/doc-tree/components/DocSubPageItem.tsx

@@ -17,6 +17,7 @@ import {
 } from '@/features/docs/doc-management';
 import { DocIcon } from '@/features/docs/doc-management/components/DocIcon';
 import { useActionableMode } from '@/features/docs/doc-tree/hooks/useActionableMode';
+import { useLoadChildrenOnOpen } from '@/features/docs/doc-tree/hooks/useLoadChildrenOnOpen';
 import { useLeftPanelStore } from '@/features/left-panel';
 import { useResponsiveStore } from '@/stores';
 
@@ -45,8 +46,8 @@ export const DocSubPageItem = (props: TreeViewNodeProps<Doc>) => {
   const { t } = useTranslation();
 
   const [menuOpen, setMenuOpen] = useState(false);
-
-  const isActive = node.isFocused || menuOpen;
+  const isSelectedNow = treeContext?.treeData.selectedNode?.id === doc.id;
+  const isActive = node.isFocused || menuOpen || isSelectedNow;
 
   const router = useRouter();
   const { togglePanel } = useLeftPanelStore();
@@ -89,13 +90,25 @@ export const DocSubPageItem = (props: TreeViewNodeProps<Doc>) => {
     }
   };
 
-  useKeyboardActivation(['Enter', ' '], isActive, handleActivate, true);
+  useKeyboardActivation(
+    ['Enter', ' '],
+    isActive && !menuOpen,
+    handleActivate,
+    true,
+  );
+  useLoadChildrenOnOpen(
+    node.data.value.id,
+    node.isOpen,
+    treeContext?.treeData.handleLoadChildren,
+    treeContext?.treeData.setChildren,
+    (doc.children?.length ?? 0) > 0 || doc.childrenCount === 0,
+  );
 
   // prepare the text for the screen reader
   const docTitle = doc.title || untitledDocument;
   const hasChildren = (doc.children?.length || 0) > 0;
   const isExpanded = node.isOpen;
-  const isSelected = treeContext?.treeData.selectedNode?.id === doc.id;
+  const isSelected = isSelectedNow;
 
   const ariaLabel = `${docTitle}${hasChildren ? `, ${isExpanded ? t('expanded') : t('collapsed')}` : ''}${isSelected ? `, ${t('selected')}` : ''}`;
 
@@ -155,6 +168,15 @@ export const DocSubPageItem = (props: TreeViewNodeProps<Doc>) => {
         .row.preview & {
           background-color: inherit;
         }
+
+        /* Ensure actions are visible when hovering the whole item container */
+        &:hover {
+          .light-doc-item-actions {
+            display: flex;
+            opacity: 1;
+            visibility: visible;
+          }
+        }
       `}
     >
       <TreeViewItem {...props} onClick={handleActivate}>

src/frontend/apps/impress/src/features/docs/doc-tree/components/DocTreeItemActions.tsx

@@ -151,7 +151,7 @@ export const DocTreeItemActions = ({
   };
 
   useDropdownFocusManagement({
-    isOpen: isOpen || false,
+    isOpen: !!isOpen,
     docId: doc.id,
     actionsRef,
   });

src/frontend/apps/impress/src/features/docs/doc-tree/hooks/useLoadChildrenOnOpen.ts

@@ -0,0 +1,55 @@
+import { useEffect, useRef } from 'react';
+
+/**
+ * Lazily loads children for a tree node the first time it is expanded.
+ * Works for both mouse and keyboard expansions.
+ */
+export const useLoadChildrenOnOpen = <T>(
+  nodeId: string,
+  isOpen: boolean,
+  handleLoadChildren?: (id: string) => Promise<T[]>,
+  setChildren?: (id: string, children: T[]) => void,
+  isAlreadyLoaded?: boolean,
+) => {
+  const hasLoadedRef = useRef(false);
+
+  // Reset the local loaded flag when the node id changes
+  useEffect(() => {
+    hasLoadedRef.current = false;
+  }, [nodeId]);
+
+  useEffect(() => {
+    if (!isOpen) {
+      return;
+    }
+    if (isAlreadyLoaded) {
+      hasLoadedRef.current = true;
+      return;
+    }
+    if (hasLoadedRef.current) {
+      return;
+    }
+    if (!handleLoadChildren || !setChildren) {
+      return;
+    }
+
+    let isCancelled = false;
+    // Mark as loading to prevent repeated fetches/renders that can cause flicker
+    hasLoadedRef.current = true;
+    void handleLoadChildren(nodeId)
+      .then((children) => {
+        if (isCancelled) {
+          return;
+        }
+        setChildren(nodeId, children);
+      })
+      .catch(() => {
+        // allow retry on next open
+        hasLoadedRef.current = false;
+      });
+
+    return () => {
+      isCancelled = true;
+    };
+  }, [isOpen, nodeId, handleLoadChildren, setChildren, isAlreadyLoaded]);
+};