Refactor XL Vask module for better null handling and primary item validation

- Improved null safety by updating product ID retrieval logic in parsers and usage logs.
- Enhanced primary wash item selection with stricter checks for valid product types.
- Adjusted import date modifier in `importUsageLogs` for extended range (`-7 day`).
- Streamlined product and user association in order creation with additional validations.
- Removed redundant checks and refined permission handling in import tasks.

services/nginx/app/objects/users_o.php

@@ -682,6 +682,7 @@ class users_o extends db
      */
     public function getCustomPrice(int $object_id, bool $is_category = false): int|null
     {
+        self::requireSelected();
         // Get the custom price for the product
         $discount = $this->price_overrides->setUser($this->id)->getPrice($is_category, $object_id);
         // If the is_category is false, check if there is a custom price for the category that the product belongs to