Add Atropos Integration

[RUFFY-369]

Description

I wanted to suggest adding support (or at least an example integration) for Atropos

Why this matters

Atropos is becoming a critical component for Reasoning-centric RL (CoT), particularly for:

• Verifiable Reasoning tasks (Math, Code, Logic)
• Deep Reasoning Expansion
• Scalable feedback loops for complex agentic workflows

Impact

While the current ROCK examples are great, having a similar integration for Atropos would:

• Broaden ROLL's usability: for the "Reasoning Frontier" in LLM research.
• Decoupled Scalability: Leverage Atropos' microservice architecture to keep high-concurrency rollouts independent of the main training loop, ensuring maximum GPU utilization during complex reasoning tasks.

I have already verified this integration locally with a 100-step "Golden Run" (expanding thinking tokens from 218 to 330) and have a PR ready for submission.