parliamentary: rebuild from IPI PAN's PPC TEI dump, official speakers only (v0.2.6 rights audit) (#108)

sejm_api: cut the "Przebieg posiedzenia" trailers, split appended statements (amends #69, v2#57) (#83)

sejm_api: state the contributor snapshot in provenance (v0.2.6, v2#57) (#69)

Add source: sejm_api — contemporary parliamentary speeches (2023 onward) (#16)