fix: Correct menu logic for portfolio value update and system exit

src/trading/main.py

@@ -145,6 +145,17 @@ def main():
             print(f"\nRemoved position: {symbol}")
             
         elif choice == "5":
+            new_value = get_float_input("Enter new portfolio value: $")
+            new_cash = get_float_input("Enter new cash balance: $")
+            notes = input("Notes (optional): ")
+            if new_value and new_cash:
+                portfolio_value = new_value
+                cash_balance = new_cash
+                update_portfolio_value(portfolio_value, cash_balance, notes)
+                print(f"\nPortfolio value updated: ${portfolio_value:.2f}")
+                print(f"Cash balance updated: ${cash_balance:.2f}")
+            
+        elif choice == "6":
             print("\nExiting Trading Management System")
             break