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/strategies/rsi_strategy.py

@@ -3,7 +3,7 @@
 Estrategia basada en RSI
 """
 import pandas as pd
-from ..backtest.strategy import Strategy, Signal, calculate_rsi
+from ..core.strategy import Strategy, Signal, calculate_rsi
 
 class RSIStrategy(Strategy):
     """