PPO Helpers (Discrete Actions)

Umbrella import for TorchLean’s PPO rollout/training helpers.

The PPO runtime code is organized around:

• NN.Runtime.RL.PPO.Rollout: rollout record + minibatch conversion (GAE/returns live in Runtime.RL.Core).
• NN.Runtime.RL.PPO.Collect: data collection from Runtime.RL.Gymnasium.Session.

References:

• Schulman et al., "Proximal Policy Optimization Algorithms" (2017): https://arxiv.org/abs/1707.06347
• Schulman et al., "High-Dimensional Continuous Control Using Generalized Advantage Estimation" (2015): https://arxiv.org/abs/1506.02438