Get a Zappos product's full detail

Returns one Zappos product's full detail: name, brand, description, category, breadcrumbs, pricing, images, aggregate rating with a 1-5 star breakdown, up to two featured customer reviews with real author/date/body/rating, reviewer-submitted fit feedback for size/width/arch (each response option's own share of respondents plus the most common answer), and every sibling color variant with its own price. productId is taken from a search result's product_id field or a product page's URL. colorId is optional and selects a specific color variant; an omitted or invalid colorId still resolves the base product using a real color variant rather than failing. An unrecognized productId returns 404.