Add per-node execution timeout support to taskflow

Add per-node execution timeout support to taskflow: a task in MiMo-V2.6-RL-oss: Agentic RL Environments (MiMo RL release). Operators want individual task nodes to be guarded by an execution timeout. When a node runs longer than its configured limit, the system should be able to react automatically…

The task

Operators want individual task nodes to be guarded by an execution timeout. When a node runs longer than its configured limit, the system should be able to react automatically according to a per-node strategy. This change is about the building blocks of that feature — the…

Part of XiaomiMiMo/MiMo-V2.6-RL-oss.