SOTOPIA-S4: a user-friendly system for flexible, customizable, and large-scale social simulation. - Xuhui Zhou; Zhe Su; Sophie Feng; Jiaxu Zhou; Jen-tse Huang 001; Hsien-Te Kao; Spencer Lynch; Svitlana Volkova; Tongshuang Sherry Wu; Anita Woolley; Hao Zhu 011; Maarten Sap (CoRR, 2025)