Yu Li Qiang Hu Yao Zhang Lili Quan Jiongchi Yu Junjie Wang DynaTrust: Defending Multi-Agent Systems Against Sleeper Agents via Dynamic Trust Graphs. 2026 March abs/2603.15661 CoRR https://doi.org/10.48550/arXiv.2603.15661 db/journals/corr/corr2603.html#abs-2603-15661 streams/journals/corr