fix期权链 Delta 改为从 opt-summary 拉取。

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

tests/test_options_delta_fields.py

@@ -1,10 +1,27 @@
 # -*- coding: utf-8 -*-
 import unittest
 
-from lib.exchange.okx_options_lib import format_position_row
+from lib.exchange.okx_options_lib import format_position_row, option_delta_from_summary
 
 
 class OptionsDeltaFieldsTests(unittest.TestCase):
+    def test_delta_prefers_summary_delta_bs(self):
+        self.assertAlmostEqual(
+            option_delta_from_summary({"deltaBS": "0.55", "delta": "12.3"}),
+            0.55,
+            places=4,
+        )
+
+    def test_delta_falls_back_to_ticker(self):
+        self.assertAlmostEqual(
+            option_delta_from_summary({}, ticker={"delta": "-0.22"}),
+            -0.22,
+            places=4,
+        )
+
+    def test_delta_none_when_missing(self):
+        self.assertIsNone(option_delta_from_summary({}, ticker={}))
+
     def test_format_position_exposes_delta_bs(self):
         row = format_position_row(
             {