Adds a new cross_asset_correlation module with:
- CorrelationAnalyzer: Pearson, Spearman, Kendall, DCC-GARCH, wavelet
coherence, and lead-lag correlation analysis
- MultiAssetProcessor: multi-asset class data loading, returns calculation,
resampling, hierarchical/graph-based asset grouping
- CorrelationRegimeDetector: regime detection via rolling volatility,
changepoint, clustering, and simplified Markov switching; crisis period
detection and regime transition prediction
Also adds scipy, scikit-learn, PyWavelets, and networkx as dependencies.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>