KAT-Coder-V2 Technical Report. - Fengxiang Li; Han Zhang; Haoyang Huang; Jinghui Wang; Jinhua Hao; Kun Yuan; Mengtong Li; Minglei Zhang; Pengcheng Xu; Wenhao Zhuang; Yizhen Shao; Zongxian Feng; et al. (CoRR, 2026)