refactor: enhance Optuna backtesting framework, optimize orderbook filtering, and update database management utilities.

kis_trader/backtest/scalping_backtest_common.py

@@ -5,6 +5,7 @@
 """
 from __future__ import annotations
 
+import os
 from datetime import datetime
 from typing import Any, Dict, List, Optional, Tuple
 
@@ -175,6 +176,8 @@ def load_scalp_candles_by_code(
         )
         return candles_by_code, total_candles
 
+    candle_src = os.environ.get("CANDLE_SOURCE", "kis") or "kis"
+
     codes_raw = db.conn.execute(
         "SELECT DISTINCT code FROM ws_candles WHERE timeframe=1 "
         "AND candle_time >= %s AND candle_time <= %s ORDER BY code",