Add WeCom markdown alerts and keep target exits while strategy is paused.

Notify open/close/start/pause/fault with SIM vs LIVE venue labels; configure webhook in Settings.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/app/config.py

@@ -77,6 +77,10 @@ class Settings(BaseSettings):
     option_qty_eth: float = 2.0
     db_path: str = ""  # empty -> backend/data/hedge.db
 
+    # 企业微信群机器人
+    wecom_enabled: bool = False
+    wecom_webhook_url: str = ""
+
     @property
     def is_sim(self) -> bool:
         return self.mode.strip().upper() != "LIVE"