Sell residual options at latest bid via IOC limit, not market.

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

backend/app/live/okx_trade.py

@@ -157,6 +157,36 @@ class OkxTradeClient:
         fill = self._wait_fill(inst_id, ord_id)
         return fill
 
+    def place_ioc(
+        self,
+        *,
+        inst_id: str,
+        side: str,  # buy|sell
+        sz: str,
+        px: float | str,
+        td_mode: str,
+        pos_side: str | None = None,
+        reduce_only: bool = False,
+    ) -> LiveFill:
+        """限价 IOC：残留回收等场景按指定买一/卖一吃单，不成交部分立即取消。"""
+        body: dict[str, Any] = {
+            "instId": inst_id,
+            "tdMode": td_mode,
+            "side": side,
+            "ordType": "ioc",
+            "sz": str(sz),
+            "px": str(px),
+        }
+        if pos_side:
+            body["posSide"] = pos_side
+        if reduce_only:
+            body["reduceOnly"] = True
+        rows = self._request("POST", "/api/v5/trade/order", body)
+        if not rows:
+            raise RuntimeError("OKX IOC 下单无返回")
+        ord_id = str(rows[0].get("ordId") or "")
+        return self._wait_fill(inst_id, ord_id)
+
     def _fill_from_order_row(self, inst_id: str, ord_id: str, row: dict[str, Any]) -> LiveFill:
         avg = safe_float(row.get("avgPx")) or 0.0
         sz = safe_float(row.get("accFillSz")) or safe_float(row.get("sz")) or 0.0