feat: refine frontend folder management and display by merging folder tree data.

frontend/src/documents/data/useDocumentsWorkspace.ts

@@ -57,7 +57,6 @@ import { listFolderContents } from '../../lib/api/apiClient';
 import { useApi } from '../../lib/context/ApiContext';
 import { useWorkspaceSelection } from '../../app/useWorkspaceSelection';
 import useDocumentPreview from '../../app/useDocumentPreview';
-import { createRootNode } from '../../app/workspaceUtils';
 import type { DocumentId, FolderNodeId, Identifier } from '../../types/identifiers';
 
 const EntryType = Object.freeze({
@@ -250,7 +249,6 @@ const useDocumentsWorkspace = ({
   });
   const {
     folderNodes,
-    setFolderNodes,
     selectedFolder,
     setSelectedFolder,
     currentFolderName,
@@ -261,6 +259,7 @@ const useDocumentsWorkspace = ({
   const folderState = {
     ...folderStateRaw,
     setCreatingFolder,
+    foldersManager,
   };
 
   const [currentSubfolders, setCurrentSubfolders] = useState<Array<{ id?: FolderNodeId; name?: string | null;[key: string]: unknown }>>([]);
@@ -299,7 +298,10 @@ const useDocumentsWorkspace = ({
         if (includeDocuments) {
           setDocuments((data.documents || []) as Document[]);
         }
-        setCurrentSubfolders((data.subfolders || []) as any[]);
+
+        const subfolders = (data.subfolders || []) as any[];
+        setCurrentSubfolders(subfolders);
+        foldersManager.ingest(subfolders);
 
         if (includeDocuments) {
           setSelectedEntries((prev) => reconcileSelectionWithFolderData(
@@ -316,6 +318,7 @@ const useDocumentsWorkspace = ({
       setCurrentSubfolders,
       reconcileSelectionWithFolderData,
       selectedFolderRef,
+      foldersManager,
     ]
   );
 
@@ -580,8 +583,6 @@ const useDocumentsWorkspace = ({
   });
 
   const resetWorkspaceState = useCallback(() => {
-    const rootNode = createRootNode();
-    setFolderNodes(new Map([[rootNode.id, rootNode]]));
     setSelectedFolder('root');
     setCurrentSubfolders([]);
     setDocuments([]);
@@ -617,7 +618,6 @@ const useDocumentsWorkspace = ({
     setFocusedDocumentId,
     setSelectedEntries,
     setSelectionOrder,
-    setFolderNodes,
     setSelectedFolder,
     setCurrentSubfolders,
     setDocuments,
@@ -637,9 +637,10 @@ const useDocumentsWorkspace = ({
 
   useEffect(() => {
     if (appStatus === 'logged-out' || appStatus === 'selecting-tenant') {
+      foldersManager.invalidateTree();
       resetWorkspaceState();
     }
-  }, [appStatus, resetWorkspaceState]);
+  }, [appStatus, resetWorkspaceState, foldersManager]);
 
 
   const removeDocumentsFromCaches = useCallback(