Details
repeatability() reports the repeatability R = (Va + Vpe) / Vp of the
opt-in, experimental repeatability (permanent-environment) model. Vp is
Va + Vpe + Ve; fixed-effect variance is not in Vp. On the same fit,
heritability() is Va / Vp. It works
for hsquared_fit objects fitted with
engine_control = list(target = "repeatability").
Separating sigma_a2 from sigma_pe2 needs repeated records per
individual; see ?hs_control (target = "repeatability") for that
identifiability requirement.