fix: ContactsList canAccess fallback + ContactFolderTree error handling with toast

frontend/src/components/contacts/ContactFolderTree.tsx

@@ -12,6 +12,7 @@ import {
 import { buildFolderTree, type ContactFolderTreeNode, type ContactFolder } from '@/api/contactFolders';
 import { ChevronRight, Folder, MoreVertical, Palette, Pencil, Pin, Plus, Shield, Tag, Trash2, Users } from 'lucide-react';
 import { FolderPermissionDialog } from './FolderPermissionDialog';
+import { useToast } from '@/components/ui/Toast';
 
 export type ContactFilter = 'all' | 'company' | 'person' | `tag:${string}` | `folder:${string}`;
 
@@ -267,6 +268,7 @@ export function ContactFolderTree({
   onMultiSelectChange,
 }: ContactFolderTreeProps) {
   const { t } = useTranslation();
+  const toast = useToast();
   const [tagsOpen, setTagsOpen] = useState(true);
   const [dropdown, setDropdown] = useState<DropdownState | null>(null);
   const [colorPicker, setColorPicker] = useState<{ folderId: string; color: string } | null>(null);
@@ -303,19 +305,34 @@ export function ContactFolderTree({
   const handleNewFolder = () => {
     const name = prompt('Ordnername:');
     if (!name) return;
-    createFolderMut.mutate({ name });
+    createFolderMut.mutate({ name }, {
+      onError: (err: any) => {
+        const msg = err?.response?.data?.detail?.detail || err?.response?.data?.detail || err?.message || 'Fehler beim Anlegen';
+        toast.error(typeof msg === 'string' ? msg : 'Fehler beim Anlegen des Ordners');
+      },
+    });
   };
 
   const handleRename = (id: string) => {
     const folder = folderList.find((f) => f.id === id);
     const newName = prompt('Neuer Name:', folder?.name || '');
     if (!newName) return;
-    updateFolderMut.mutate({ id, data: { name: newName } });
+    updateFolderMut.mutate({ id, data: { name: newName } }, {
+      onError: (err: any) => {
+        const msg = err?.response?.data?.detail?.detail || err?.response?.data?.detail || err?.message || 'Fehler beim Umbenennen';
+        toast.error(typeof msg === 'string' ? msg : 'Fehler beim Umbenennen');
+      },
+    });
   };
 
   const handleDelete = (id: string) => {
     if (!confirm('Ordner l\u00f6schen? Kontakte bleiben erhalten, werden aber keinem Ordner mehr zugeordnet.')) return;
-    deleteFolderMut.mutate(id);
+    deleteFolderMut.mutate(id, {
+      onError: (err: any) => {
+        const msg = err?.response?.data?.detail?.detail || err?.response?.data?.detail || err?.message || 'Fehler beim L\u00f6schen';
+        toast.error(typeof msg === 'string' ? msg : 'Fehler beim L\u00f6schen');
+      },
+    });
   };
 
   const handleColor = (id: string) => {

frontend/src/pages/ContactsList.tsx

@@ -45,6 +45,7 @@ export function ContactsListPage() {
   const { hasPermission } = usePermission();
   const authUser = useAuthStore((state) => state.user);
   const canAccess = (perm: string): boolean => {
+    if (!authUser?.permissions && authUser?.is_system_admin === undefined) return true;
     return hasPermission(perm);
   };