fix期权下单默认按可用余额打满；持仓上限/缓冲/门控秒数默认值调整。

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

lib/options/options_position_limit_lib.py

@@ -6,12 +6,12 @@ from typing import Any, Optional, Sequence
 
 
 def options_max_active_positions() -> int:
-    """同时持有的期权合约笔数上限;0=不限制.热更读 env."""
-    raw = os.getenv("OKX_OPTIONS_MAX_ACTIVE_POSITIONS", "0")
+    """同时持有的期权合约笔数上限;0=不限制.默认 1(一次一仓).热更读 env."""
+    raw = os.getenv("OKX_OPTIONS_MAX_ACTIVE_POSITIONS", "1")
     try:
         v = int(float(str(raw).strip()))
     except (TypeError, ValueError):
-        return 0
+        return 1
     return max(0, v)