feat(purchase): implement purchase limit enforcement and custom exception handling

app/Domains/Catalog/Resources/CatalogItemDetailResource.php

@@ -38,10 +38,6 @@ class CatalogItemDetailResource extends JsonResource
             'max_units_per_user' => $this->max_units_per_user,
             'has_tickets' => $this->has_tickets,
             'attributes' => $this->attributesData(),
-            'stock_tecnico' => $this->when(
-                $selectedVariant === null,
-                fn () => $this->availableStock(),
-            ),
             'maximum_addable_quantity' => $this->when(
                 $selectedVariant === null,
                 fn () => $this->maximumAddable($this->availableStock()),
@@ -172,7 +168,6 @@ class CatalogItemDetailResource extends JsonResource
             'event_dates' => $eventDates->map(fn ($eventDate): string => $eventDate->date->format('Y-m-d'))->values(),
             'descripcion' => $variant->getDescription(),
             'precio' => number_format($variant->getPrice(), 2, '.', ''),
-            'stock_tecnico' => $this->variantStock($variant),
             'maximum_addable_quantity' => $this->maximumAddable($this->variantStock($variant)),
             'values' => $values,
         ];