Realign ATM to current mark before open; skip while in position.

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

backend/app/sim/matcher.py

@@ -412,7 +412,11 @@ class Matcher:
                 perp_upl = (perp_entry - float(mark)) * perp_qty
 
         option_side = str(pos["option_side"])
-        oq = snap.call if option_side == "call" else snap.put
+        # 优先用持仓合约盘口，避免 ATM 切换后盯错合约
+        opt_inst = str(pos.get("option_inst_id") or "")
+        oq = gw.cache.get(opt_inst) if opt_inst else None
+        if oq is None:
+            oq = snap.call if option_side == "call" else snap.put
         opt_mark = None
         if oq:
             opt_mark = oq.bid or oq.mark_px