refactor: introduce dedicated identifier types for improved clarity and type safety

frontend/src/documents/SelectionAssignmentMenu.tsx

@@ -5,18 +5,18 @@ import { CheckIcon, CircleDashedCheckIcon, PlusIcon } from '../ui/icons';
 export type AssignmentState = 'all' | 'partial' | 'none';
 
 export interface SelectionAssignmentMenuItem {
-  id?: string | number;
+  id?: string;
   label?: string;
   state?: AssignmentState;
   count?: number | null;
   total?: number | null;
   color?: string | null;
-  value?: string | number;
+  value?: string;
   payload?: unknown;
 }
 
 export interface NormalizedSelectionAssignmentItem {
-  id: string | number;
+  id: string;
   label: string;
   state: AssignmentState;
   count: number | null;
@@ -105,7 +105,7 @@ const SelectionAssignmentMenu: React.FC<SelectionAssignmentMenuProps> = ({
   const inputRef = useRef<HTMLInputElement | null>(null);
   const [query, setQuery] = useState('');
   const [pending, setPending] = useState(false);
-  const [sortSnapshot, setSortSnapshot] = useState<Array<string | number> | null>(null);
+  const [sortSnapshot, setSortSnapshot] = useState<Array<string> | null>(null);
 
   const {
     isOpen,
@@ -175,10 +175,10 @@ const SelectionAssignmentMenu: React.FC<SelectionAssignmentMenuProps> = ({
 
   const orderedItems = useMemo(() => {
     if (freezeSortOnOpen && sortSnapshot && sortByState) {
-      const itemMap = new Map<string | number, NormalizedSelectionAssignmentItem>(
+      const itemMap = new Map<string, NormalizedSelectionAssignmentItem>(
         sortedByStateItems.map((item) => [item.id, item]),
       );
-      const seen = new Set<string | number>();
+      const seen = new Set<string>();
       const fromSnapshot = sortSnapshot
         .map((id) => {
           const entry = itemMap.get(id);