List bazaar items

Returns bazaar items with their current buy/sell prices and available stock. Each item carries its category (top-level, e.g. farming) and subcategory (e.g. wheat). Results are in a stable item-id order, so paging with offset/limit is a consistent, non-overlapping walk of the full set; total is the full item count. By default the list also includes every sellable item that currently has no offer, as a 0/0/0 entry (set include_empty=false for active-only). The complete sellable set + category tree is also available on /market/catalog.