fixing and styleing

src/app/models/category.model.ts

@@ -14,7 +14,10 @@ export interface Subcategory {
   visible: boolean;
   priority: number;
   img?: string;
+  /** Root-level category this subcategory belongs to */
   categoryId: string;
+  /** Direct parent ID — could be a category ID or a parent subcategory ID */
+  parentId?: string;
   itemCount?: number;
   subcategories?: Subcategory[];
   hasItems?: boolean;