修复期权开平仓时间按 UTC 入库导致复盘K线标记偏8小时：统一业务时区并一次性迁移。

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

lib/exchange/okx_options_lib.py

@@ -214,16 +214,10 @@ def option_history_row_key(
 
 
 def _ms_to_iso(ms: Any) -> str | None:
-    val = _safe_float(ms)
-    if val is None or val <= 0:
-        return None
-    try:
-        from datetime import datetime, timezone
+    """OKX ms → 业务时区墙钟(默认 Asia/Shanghai);勿用系统本地时区."""
+    from lib.options.options_time_lib import ms_to_options_app_str
 
-        dt = datetime.fromtimestamp(int(val) / 1000.0, tz=timezone.utc).astimezone()
-        return dt.strftime("%Y-%m-%d %H:%M:%S")
-    except (TypeError, ValueError, OSError):
-        return None
+    return ms_to_options_app_str(ms)
 
 
 def option_instrument_meta_cached(