Realign market pair when hedge mode switches.

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

backend/app/api/settings.py

@@ -403,6 +403,9 @@ async def put_strategy_settings(
     data = body.model_dump(exclude_none=True)
     equity_to_apply: float | None = None
     switch_to: str | None = None
+    old_hedge = str(
+        db.get_setting("hedge_mode", s.hedge_mode) or s.hedge_mode or "perp_option"
+    ).strip().lower()
 
     if "exchange" in data:
         new_ex = normalize_exchange_name(str(data.pop("exchange")))
@@ -611,6 +614,18 @@ async def put_strategy_settings(
                 detail=f"交易所已切换为 {switch_to}，但行情重连失败: {e}",
             ) from e
 
+    new_hedge = str(
+        db.get_setting("hedge_mode", s.hedge_mode) or s.hedge_mode or "perp_option"
+    ).strip().lower()
+    if new_hedge != old_hedge and switch_to is None:
+        # 对冲模式切换：强制按新模式重对齐监控合约（ATM ↔ 虚值）
+        try:
+            from ..strategy.session import get_session
+
+            await get_session().ensure_atm_async(force=True)
+        except Exception:
+            pass
+
     return _read_settings()