Fetches full details for a specific US TikTok Shop product by its URL, including stock levels and affiliate videos. Returns product_info with product_base (title, images, sold_count, price), skus (variants with exact stock counts plus TikTok's sku_name and gtin when available), and product_detail_review (product_rating, review_count, sample reviews). gtin contains gtin_type and gtin_code, or is null when TikTok does not provide a barcode. The response also includes shop_info (shop_name, shop_rating, followers_count) and related_videos (affiliate TikToks promoting the pr Uses the caller's OpenAny gateway credentials. Charges and authorization are determined by the gateway.