fix: Define previous_price to resolve undefined name error in function

src/screener/t_atr_ema.py

@@ -28,6 +28,7 @@ def check_atr_ema_buy_condition(df: pd.DataFrame) -> bool:
     """Check if price is below EMA and moving up through lower ATR band"""
     # Get latest values from DataFrame
     last_price = df.iloc[-1]
+    previous_price = df.iloc[-2]  # Get the previous row for comparison
     results = ThreeATREMAIndicator().calculate(df)  # Ensure results are calculated here
 
     # Check if price is below EMA and has started moving up