Support SAO (Single-Rollout Asynchronous Optimization)

[mccatec]

Checklist / 检查清单

• I have searched existing issues, and this is a new feature request. / 我已经搜索过现有的 issues，确认这是一个新的 Feature Request。

Feature Request Description / Feature Request 描述

As revealed by Z.ai, SAO (https://arxiv.org/pdf/2607.07508) is the secret ingredient behind the success of GLM-5.2. It employs a PPO-like method to address the issue that candidate trajectories within the same group become incomparable when they diverge significantly. SAO is expected to be better suited for long-horizon agentic training.

Pull Request / Pull Request 信息

No response