Get full details for a single product by ID. Returns attributes: structured specs read from retailer titles, each name mapping to {status, value, sources}; a conflicting one has values: [{value, sources}] instead of value and sources. Names and units as in the search constraints argument. status: 'confirmed' = two or more retailers state the same value; 'inferred' = one retailer's title states it; 'conflicting' = retailers state different values (none is picked, tell the user they disagree; a retailer can appear under two values, so read offers[].title to see which listing states which); a missing name = unknown. Also returns specs.description, the retailer's own prose: use it only for details attributes do not cover (processor, GPU, ports, weight, battery, features); if it doesn't give a detail, tell the user it isn't listed. It can describe another configuration or a maximum ('up to 32GB'), so it never overrides or fills in an attribute: if an attribute is missing or conflicting, that spec is unknown or unconfirmed, and you may mention what the description says only as 'the retailer's description mentions X, unconfirmed'. It also returns pricing, availability, delivery time, and all retailer offers with per-retailer pricing (offers[].stock is a unit count only when the retailer supplies one, otherwise null). Accepts both canonical product IDs and original retailer offer IDs. Use this after search_products only for your final 1-3 picks, and only when you need what search lacks: details only the description has, or every retailer's offer and buy link. Search results already carry attributes to compare specs.