feat(catalog): add max_units_per_user field to catalog items and implement purchase limit validation

app/Domains/Catalog/Models/CatalogItem.php

@@ -31,6 +31,7 @@ use Illuminate\Database\Eloquent\Relations\HasMany;
     'descripcion',
     'precio',
     'inventory_policy',
+    'max_units_per_user',
     'has_tickets',
     'validity_time_id',
 ])]
@@ -59,6 +60,7 @@ class CatalogItem extends Model
             'type' => CatalogItemType::class,
             'precio' => 'decimal:2',
             'inventory_policy' => InventoryPolicy::class,
+            'max_units_per_user' => 'integer',
             'has_tickets' => 'boolean',
             'validity_time_id' => 'integer',
         ];