feat: finalize portfolio system and quantitative validation- Finalized MA_Crossover(30,100) and TrendFiltered_MA(30,100,ADX=15)

- Implemented portfolio engine with risk-based allocation (50/50)
- Added equity-based metrics for system-level evaluation
- Validated portfolio against standalone strategies
- Reduced max drawdown and volatility at system level
- Quantitative decision closed before paper trading phase

tests/dam_test.py

@@ -12,7 +12,7 @@ import pandas as pd
 sys.path.insert(0, str(Path(__file__).parent.parent))
 
 from src.data.storage import StorageManager
-from src.backtest.walk_forward import WalkForwardValidator
+from src.core.walk_forward import WalkForwardValidator
 from src.strategies import MovingAverageCrossover
 
 def setup_environment():