Api Keys Summary Filtered

Request body for POST-for-filtering on /api/keys/list/ and /api/keys/summary/ — distinguishes the filter POST from key creation.

filters is an open dict (matches DatasetFilterRequestSerializer): the filter shape is dynamic and the frontend owns a typed FilterRequest, so a strict per-field schema would only fight the FE's filter types.

Response body for /api/keys/summary/ — total matching API keys.