feat: enhance variant handling in selector and layout components for improved display and selection

src/app/core/services/cart/cart.interface.ts

@@ -4,11 +4,21 @@ export interface CartItemProduct {
   variants?: CartItemVariant[];
 }
 
+export interface CartItemVariantOption {
+  value: string;
+  label: string;
+}
+
+export type CartItemVariantValue =
+  | string
+  | CartItemVariantOption
+  | Array<string | CartItemVariantOption>;
+
 export interface CartItemVariant {
   id: number;
   precio: string;
   stock_tecnico: number | null;
-  values: Record<string, string | string[]>;
+  values: Record<string, CartItemVariantValue>;
 }
 
 export interface CartItem {