feat: implement direct purchase functionality and enhance product buy events

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

@@ -14,7 +14,7 @@
     </div>
 
     <div class="product-vertical-with-cart-card__actions">
-      <app-button variant="primary" (click)="buy.emit()">Comprar</app-button>
+      <app-button variant="primary" (click)="onBuy()">Comprar</app-button>
       <app-button variant="secondary" (click)="onAddToCart()"> Agregar al carrito </app-button>
     </div>
   </div>

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

@@ -17,7 +17,7 @@ export class ProductVerticalWithCartCardComponent {
 
   readonly quantity = model<number>(1);
 
-  readonly buy = output<void>();
+  readonly buy = output<{ quantity: number }>();
   readonly addToCart = output<{ quantity: number }>();
 
   protected readonly formattedPrice = computed(() => this.formatCurrency(this.price()));
@@ -26,6 +26,10 @@ export class ProductVerticalWithCartCardComponent {
     this.addToCart.emit({ quantity: this.quantity() });
   }
 
+  protected onBuy(): void {
+    this.buy.emit({ quantity: this.quantity() });
+  }
+
   private formatCurrency(value: number): string {
     const rounded = Math.round(value);
     const parts = rounded.toString().split('.');