feat: enhance product ticket selector and vertical cart card components

- Refactor ProductTicketSelectorComponent to improve variant selection logic and error handling.
- Introduce a new signal for variant attributes and manage variant loading more efficiently.
- Update the UI to reflect saving state in ProductVerticalWithCartCardComponent, preventing actions while saving.
- Adjust button text based on saving state for better user feedback.

src/app/shared/components/product-vertical-with-cart-card/product-vertical-with-cart-card.component.html

@@ -36,10 +36,10 @@
       </app-button>
       <app-button
         variant="secondary"
-        [disabled]="hasVariants() && selectedVariant() === null"
+        [disabled]="saving() || (hasVariants() && selectedVariant() === null)"
         (click)="onAddToCart()"
       >
-        Agregar al carrito
+        {{ saving() ? 'Guardando' : 'Agregar al carrito' }}
       </app-button>
     </div>
   </div>

src/app/shared/components/product-vertical-with-cart-card/product-vertical-with-cart-card.component.ts

@@ -24,6 +24,7 @@ export class ProductVerticalWithCartCardComponent {
   readonly description = input<string>('');
   readonly price = input<number>(0);
   readonly variants = input<VerticalCartVariant[]>([]);
+  readonly saving = input(false);
 
   readonly quantity = model<number>(1);
   readonly selectedVariant = model<number | null>(null);
@@ -46,6 +47,10 @@ export class ProductVerticalWithCartCardComponent {
   protected readonly hasVariants = computed(() => this.variants().length > 0);
 
   protected onAddToCart(): void {
+    if (this.saving()) {
+      return;
+    }
+
     this.addToCart.emit({ quantity: this.quantity(), variant: this.selectedVariant() });
   }