feat: implement direct purchase functionality and enhance product buy events

src/app/shared/components/product-row-card/product-row-card.component.html

@@ -19,7 +19,7 @@
         {{ formattedPrice() }}
       </span>
       <div class="product-row-card__btn-wrapper">
-        <app-button variant="primary" (click)="buy.emit()">
+        <app-button variant="primary" (click)="onBuy()">
           Comprar
         </app-button>
       </div>

src/app/shared/components/product-row-card/product-row-card.component.ts

@@ -28,7 +28,7 @@ export class ProductRowCardComponent {
   readonly selectedVariant = model<any>(null);
 
   // Interactive events
-  readonly buy = output<void>();
+  readonly buy = output<{ quantity: number; variant: any }>();
   readonly addToCart = output<{ quantity: number; variant: any }>();
 
   constructor() {
@@ -57,6 +57,13 @@ export class ProductRowCardComponent {
     });
   }
 
+  protected onBuy(): void {
+    this.buy.emit({
+      quantity: this.quantity(),
+      variant: this.selectedVariant(),
+    });
+  }
+
   /**
    * Helper method to format currency numbers to Argentine Pesos style "$ XX.XXX".
    */