Retrieve relevant chunks.

The optional request.filters payload accepts equality checks (which also match scalars inside JSON arrays) plus the logical operators $and, $or, $nor, and $not. Field-level predicates include $eq, $ne, $in, $nin, $exists, $type, $regex, $contains, and the comparison operators $gt, $gte, $lt, and $lte. Comparison clauses evaluate typed metadata (number, decimal, datetime, or date) and raise detailed validation errors when operands cannot be coerced. Regex filters allow the optional i flag for case-insensitive matching, while $contains performs substring checks (case-insensitive by default, configurable via case_sensitive). Filters can be nested freely, for example:

{
  "$and": [
    {"category": "policy"},
    {"$or": [{"region": "emea"}, {"priority": {"$in": ["p0", "p1"]}}]}
  ]
}

Returns a list of ChunkResult objects ordered by relevance.