feat: Initialize Portfolio and load existing trades in main function

src/trading/main.py

@@ -49,6 +49,22 @@ def main():
     # Initialize calculator with current portfolio value
     calculator = PositionCalculator(account_size=portfolio_value)
     
+    # Initialize portfolio
+    portfolio = Portfolio()
+    
+    # Load existing open trades into portfolio
+    open_trades = get_open_trades()
+    for trade in open_trades:
+        position = Position(
+            symbol=trade['ticker'],
+            entry_date=trade['entry_date'],
+            entry_price=trade['entry_price'],
+            shares=trade['shares'],
+            stop_loss=trade['stop_loss'],
+            target_price=trade['target_price']
+        )
+        portfolio.add_position(position)
+
     while True:
         print("\nTrading Management System")
         print("1. Calculate Position Size")