fix: critical bugs — double fee, SL/TP atomicity, PnL race, graceful shutdown

C5: Remove duplicate entry_fee deduction in backtester (balance and net_pnl)
C1: Add SL/TP retry (3x) with emergency market close on final failure
C3: Add _close_lock to prevent PnL double recording between callback and monitor
C8: Add SIGTERM/SIGINT handler with per-symbol order cancellation before exit

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

main.py

@@ -1,4 +1,5 @@
 import asyncio
+import signal
 from datetime import datetime, timedelta, timezone
 from dotenv import load_dotenv
 from loguru import logger
@@ -21,6 +22,25 @@ async def _daily_reset_loop(risk: RiskManager):
         risk.reset_daily()
 
 
+async def _graceful_shutdown(bots: list[TradingBot], tasks: list[asyncio.Task]):
+    """모든 봇의 오픈 주문 취소 후 태스크를 정리한다."""
+    logger.info("Graceful shutdown 시작 — 오픈 주문 취소 중...")
+    for bot in bots:
+        try:
+            await asyncio.wait_for(bot.exchange.cancel_all_orders(), timeout=5)
+            logger.info(f"[{bot.symbol}] 오픈 주문 취소 완료")
+        except Exception as e:
+            logger.warning(f"[{bot.symbol}] 오픈 주문 취소 실패 (무시): {e}")
+
+    for task in tasks:
+        task.cancel()
+    results = await asyncio.gather(*tasks, return_exceptions=True)
+    for r in results:
+        if isinstance(r, Exception) and not isinstance(r, asyncio.CancelledError):
+            logger.warning(f"태스크 종료 중 예외: {r}")
+    logger.info("Graceful shutdown 완료")
+
+
 async def main():
     setup_logger(log_level="INFO")
     config = Config()
@@ -39,11 +59,35 @@ async def main():
         bots.append(bot)
 
     logger.info(f"멀티심볼 봇 시작: {config.symbols} ({len(bots)}개 인스턴스)")
-    await asyncio.gather(
-        *[bot.run() for bot in bots],
-        _daily_reset_loop(risk),
+
+    # 시그널 핸들러 등록
+    loop = asyncio.get_running_loop()
+    shutdown_event = asyncio.Event()
+
+    def _signal_handler():
+        logger.warning("종료 시그널 수신 (SIGTERM/SIGINT)")
+        shutdown_event.set()
+
+    for sig in (signal.SIGTERM, signal.SIGINT):
+        loop.add_signal_handler(sig, _signal_handler)
+
+    tasks = [
+        asyncio.create_task(bot.run(), name=f"bot-{bot.symbol}")
+        for bot in bots
+    ]
+    tasks.append(asyncio.create_task(_daily_reset_loop(risk), name="daily-reset"))
+
+    # 종료 시그널 대기 vs 태스크 완료 (먼저 발생하는 쪽)
+    shutdown_task = asyncio.create_task(shutdown_event.wait(), name="shutdown-wait")
+    done, pending = await asyncio.wait(
+        tasks + [shutdown_task],
+        return_when=asyncio.FIRST_COMPLETED,
     )
 
+    # 시그널이든 태스크 종료든 graceful shutdown 수행
+    shutdown_task.cancel()
+    await _graceful_shutdown(bots, tasks)
+
 
 if __name__ == "__main__":
     asyncio.run(main())