Retrieve relevant documents.
request.filters supports equality checks (including scalar-to-array matches) and the same operator set as
/retrieve/chunks: logical composition via $and, $or, $nor, $not, plus field predicates $eq, $ne,
$gt, $gte, $lt, $lte, $in, $nin, $exists, $type, $regex, and $contains. Use the same JSON
structure as /retrieve/chunks when expressing complex logic. Comparison operators require metadata typed as
number, decimal, datetime, or date.