refactor(frontend): Remove '/api' prefix from all API calls to align with backend URL convention

- Updated all API endpoint strings in 'frontend/src' (via sed and manual fixes) to remove the '/api/' prefix.
- Manually fixed 'Timeline.tsx' absolute URLs to use the 'api' subdomain and correct path.
- Manually fixed 'useAuth.ts' logout fetch URLs.
- Updated 'HelpApiDocs.tsx' sandbox URL.
- This change, combined with the backend URL update, fully transitions the application to use subdomain-based routing (e.g., 'http://api.lvh.me:8000/resource/') instead of path-prefix routing (e.g., 'http://api.lvh.me:8000/api/resource/').

frontend/src/components/EditTaskModal.tsx

@@ -167,7 +167,7 @@ const EditTaskModal: React.FC<EditTaskModalProps> = ({ task, isOpen, onClose, on
         }
       }
 
-      await axios.patch(`/api/scheduled-tasks/${task.id}/`, payload);
+      await axios.patch(`/scheduled-tasks/${task.id}/`, payload);
       onSuccess();
       handleClose();
     } catch (err: any) {