Measurements of $C\!P$ violation with charm hadrons at Belle and Belle II

Recent searches for $C\!P$ violation in charm-hadron decays at Belle and Belle II are presented. The measurements cover D⁺₍ₛ₎→ηh⁺, D→ππ, D⁰→ KS⁰KS⁰, and D⁰→π⁺π⁻π⁰, together with the singly Cabibbo-suppressed baryon decays Ξc⁺→Σ⁺h⁺h⁻ and Λc⁺→ ph⁺h⁻, where $h=π,K$. The Belle II analyses use the Run~1 data sample of 428\,fb⁻¹, supplemented by 980\,fb⁻¹ of Belle data for the KS⁰KS⁰ measurements. We report preliminary results for the ηh⁺ modes, complementary tests of the isospin structure of D→ππ, and an application of inclusive charm-flavor tagging. The first individual decay-rate asymmetries in these three-body charmed-baryon modes also provide tests of U-spin symmetry. All reported asymmetries are consistent with $C\!P$ symmetry within the present precision.