- Rename SlippageModel trait → MarketImpactModel to avoid name collision
with PPO's SlippageModel enum
- Wrap ThompsonSamplingState in std::sync::Mutex for interior mutability
through Arc, enabling record_outcome during inference
- Add TrafficSplitter::record_outcome() method for callers
- Cap RegimeDetectionEngine::feature_data to window_size*3 entries
- Add trailing newline to ab_testing.rs
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>