Harden env save against empty numerics; default coin margin and hedge off.

Reject blank float/int/select on save and parse env with safe helpers so options config edits cannot crash into 502; default OKX_TRADE_MODE=options and OKX_OPTIONS_MARGIN_MODE=coin.

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

lib/hedge_plan/okx_trade_mode_lib.py

@@ -48,19 +48,10 @@ def normalize_okx_trade_mode(raw: Optional[str]) -> str:
 
 
 def legacy_infer_okx_trade_mode() -> str:
-    """未配置 OKX_TRADE_MODE 时,按旧开关推断,避免已有部署行为突变."""
-    if not _env_bool("HEDGE_PLAN_ENABLED", False):
-        return MODE_OPTIONS
-    show_po = _env_bool("HEDGE_PLAN_SHOW_PERP_OPTIONS", True)
-    show_oo = _env_bool("HEDGE_PLAN_SHOW_OPTIONS_OPTIONS", True)
-    if show_po and not show_oo:
-        return MODE_PERP
-    if show_oo and not show_po:
-        return MODE_OO
-    if show_po:
-        return MODE_PERP
-    if show_oo:
-        return MODE_OO
+    """未配置 OKX_TRADE_MODE 时默认单独期权(对冲关闭).
+
+    旧 HEDGE_PLAN_* 开关不再自动打开对冲,避免误开;需显式设 OKX_TRADE_MODE=options_options.
+    """
     return MODE_OPTIONS