Write an RFC for post-training with NOOA agents

Parent

Sub-issue of #3458.

Goal

Write an RFC defining how NOOA agents participate in Gym-based post-training on top of #2096 and the CLU evaluation work in #3453.

Coordinate with Cynthia and whoever Cynthia points to for testing out the post-training readiness at scale.

Required decisions

• Define the training-ready rollout and trajectory contract.
• Define token ID, log probability, model-call lineage, reward, and failure requirements.
• Define how NOOA policy calls are routed through Gym's model server during collection.
• Define state isolation, retries, cancellation, and reproducibility requirements.
• Identify required changes in NOOA, Gym, CLU, and the selected training framework.
• Define staged implementation milestones and end-to-end readiness tests.

Acceptance criteria

• The RFC documents the current state and remaining gaps.
• Data ownership and integration boundaries are explicit.
• Evaluation-only and post-training requirements are distinguished.
• The proposal includes alternatives, risks, and unresolved decisions.
• The proposal includes measurable milestones for implementation and validation.
• Relevant NOOA, Gym, CLU, and training stakeholders review the RFC.