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

src/risk/stops/trailing_stop.py

@@ -1,7 +1,7 @@
 # src/risk/stops/trailing_stop.py
 import pandas as pd
 from src.risk.stops.base import StopLoss
-from src.backtest.trade import TradeType, Position
+from src.core.trade import TradeType, Position
 
 
 class TrailingStop(StopLoss):