Entity / external-entity name to read from.
OptionalExtraOptional SQL-ish filter expression (passed through to RunView's ExtraFilter).
OptionalFieldsOptional column projection — narrows the read for performance.
OptionalMaxOptional cap on rows returned.
OptionalOrderOptional ordering expression (passed through to RunView's OrderBy).
Read parameters for fetching rows from a named source. A subset of MJ's
RunViewParams, narrowed to what FeatureAssembly needs (read-only).