message: this is no longer needed
diff: @@ -227,17 +227,7 @@ class Searcher {
  }
  async _fieldFilter(branch, schema, aboveSegments, key, value) {
  - let field;
  -
  - if (['cardstack_source'].includes(key)) {
  - // this is an internal field (meaning it's not visible in the
  - // jsonapi records themselves) that we make available for
  - // filtering. The schema-cache uses this to avoid shadowing seed
  - // models, for example.
  - field = { queryFieldName: key, sortFieldName: key };
  - } else {
  - field = schema.fields.get(key);
  - }
  + let field = schema.fields.get(key);
  if (!field) {
  throw new Error(`Cannot filter by unknown field "${key}"`, {
  