修复主力合约识别：按持仓量判定并移除当月占位

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

market.py

@@ -51,6 +51,52 @@ def _sina_headers() -> dict:
     return {"Referer": "https://finance.sina.com.cn"}
 
 
+def _parse_sina_futures_quote(parts: list) -> Optional[dict]:
+    """解析新浪 nf_/CFF_RE_ 期货行情字段。"""
+    if len(parts) < 9:
+        return None
+    price = None
+    for idx in (8, 7, 6, 5):
+        if len(parts) > idx and parts[idx]:
+            try:
+                val = float(parts[idx])
+                if val > 0:
+                    price = val
+                    break
+            except ValueError:
+                pass
+    if price is None:
+        price = 0.0
+
+    open_interest = 0.0
+    volume = 0.0
+    if len(parts) > 13 and parts[13]:
+        try:
+            open_interest = float(parts[13])
+        except ValueError:
+            pass
+    if len(parts) > 14 and parts[14]:
+        try:
+            volume = float(parts[14])
+        except ValueError:
+            pass
+
+    prev_close = None
+    if len(parts) > 9 and parts[9]:
+        try:
+            prev_close = float(parts[9])
+        except ValueError:
+            pass
+
+    return {
+        "name": parts[0],
+        "price": price,
+        "volume": volume,
+        "open_interest": open_interest,
+        "prev_close": prev_close,
+    }
+
+
 def _fetch_sina_raw(sina_code: str) -> Optional[dict]:
     try:
         url = f"https://hq.sinajs.cn/list={sina_code}"
@@ -62,27 +108,7 @@ def _fetch_sina_raw(sina_code: str) -> Optional[dict]:
         if not body:
             return None
         parts = body.split(",")
-        if len(parts) < 9:
-            return None
-        price = float(parts[8])
-        volume = float(parts[14]) if len(parts) > 14 and parts[14] else 0
-        prev_close = None
-        if len(parts) > 9 and parts[9]:
-            try:
-                prev_close = float(parts[9])
-            except ValueError:
-                pass
-        if prev_close is None and len(parts) > 2 and parts[2]:
-            try:
-                prev_close = float(parts[2])
-            except ValueError:
-                pass
-        return {
-            "name": parts[0],
-            "price": price,
-            "volume": volume,
-            "prev_close": prev_close,
-        }
+        return _parse_sina_futures_quote(parts)
     except Exception as exc:
         logger.debug("sina fetch failed %s: %s", sina_code, exc)
         return None