Defines the column configuration for the product results table. Each
column declares its accessor, cell renderer, sort/filter functions, and
(optionally) meta.drawer to opt into a pre-search drawer accordion.
Builds a seed filter-config object from the column definitions, keyed by
column id. Each filterable column contributes one entry with its
filterVariant and an empty filterData array ready to be populated as
search results stream in.
Defines the column configuration for the product results table. Each column declares its accessor, cell renderer, sort/filter functions, and (optionally)
meta.drawerto opt into a pre-search drawer accordion.