Add 16 unit tests for Enhanced ML service components:
- EnsembleConfig::default() values (min_models, thresholds, voting)
- FeaturePreprocessor::classify_feature_type() for price, volume,
technical, sentiment, and unknown features
- FeaturePreprocessor normalization (z-score, tanh fallback, zero std_dev)
- FeaturePreprocessor default stats validation
- RuntimeModelInfo creation for all 5 model types (DQN/PPO/TFT/Mamba/LNN)
- ModelPerformanceMetrics::default() zero initialization
- FeatureNormStats volatility default bounds
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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