fix: 开仓时间读CTP OpenDate，止盈止损持久化且重启不丢失

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

sl_tp_guard.py

@@ -20,6 +20,7 @@ from vnpy_bridge import (
     ctp_list_positions,
     ctp_status,
     execute_order,
+    get_bridge,
 )
 
 logger = logging.getLogger(__name__)
@@ -478,7 +479,7 @@ def reconcile_monitors_without_position(conn, mode: str, *, grace_sec: int = 120
     """持仓已平时：关闭监控并撤销残留止盈止损挂单（新开仓 grace_sec 内不清理）。"""
     if not ctp_status(mode).get("connected"):
         return 0
-    positions = ctp_list_positions(mode)
+    positions = ctp_list_positions(mode, refresh_if_empty=False, refresh_margin=False)
     position_keys: set[tuple[str, str]] = set()
     for p in positions:
         if int(p.get("lots") or 0) <= 0:
@@ -487,6 +488,15 @@ def reconcile_monitors_without_position(conn, mode: str, *, grace_sec: int = 120
         direction = p.get("direction") or "long"
         position_keys.add((sym, direction))
 
+    if not position_keys:
+        try:
+            acc = get_bridge().get_account()
+            margin_used = float(acc.get("balance") or 0) - float(acc.get("available") or 0)
+            if margin_used > 500:
+                return 0
+        except Exception:
+            return 0
+
     now_ts = time.time()
 
     def _monitor_within_grace(mon: dict) -> bool: