Canonical integral models for Shimura varieties of toral type

We prove the Pappas-Rapoport conjecture on the existence of canonical integral models of Shimura varieties with parahoric level structure in the case where the Shimura variety is defined by a torus. As an important ingredient, we show, using the Bhatt-Scholze theory of prismatic $F$-crystals, that there is a fully faithful functor from $\mathcal{G}$-valued crystalline representations of Gal$(\bar{K}\mathrm{/}K)$ to $\mathcal{G}$-shtukas over Spd$({\mathcal{O}}_K)$, where $\mathcal{G}$ is a parahoric group scheme over ${\mathbb{Z}}_p$ and ${\mathcal{O}}_K$ is the ring of integers in a $p$-adic field $K$.