fix: restore positions on restart and fix notify env loading

- restore_positions(): read Upbit balances on startup to prevent
  double-buying after restart
- notify.py: read TOKEN/CHAT_ID inside _send() to avoid empty values
  when module is imported before load_dotenv()

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

core/notify.py

@@ -9,19 +9,19 @@ import requests
 
 logger = logging.getLogger(__name__)
 
-_TOKEN = os.getenv("TELEGRAM_TRADE_TOKEN", "")
-_CHAT_ID = os.getenv("TELEGRAM_CHAT_ID", "")
 _API = "https://api.telegram.org/bot{token}/sendMessage"
 
 
 def _send(text: str) -> None:
-    if not _TOKEN or not _CHAT_ID:
+    token = os.getenv("TELEGRAM_TRADE_TOKEN", "")
+    chat_id = os.getenv("TELEGRAM_CHAT_ID", "")
+    if not token or not chat_id:
         logger.warning("Telegram 설정 없음, 알림 스킵")
         return
     try:
         requests.post(
-            _API.format(token=_TOKEN),
-            json={"chat_id": _CHAT_ID, "text": text, "parse_mode": "HTML"},
+            _API.format(token=token),
+            json={"chat_id": chat_id, "text": text, "parse_mode": "HTML"},
             timeout=5,
         )
     except Exception as e: