VisCoder2: Building Multi-Language Visualization Coding Agents - Ni, Yuansheng; Cai, Songcheng; Chen, Xiangchao; Liang, Jiarong; LYU, Zhiheng; Deng, Jiaqi; Zou, Kai; NIE, PING; Yuan, Fei; Yue, Xiang; Chen, Wenhu (International Conference on Learning Representations, 2026)