修复期权币本位高危缺陷：开仓估量、卖回封顶、握库超时与条件单嵌套锁。

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

tests/test_spot_dust_and_sell_cap.py

@@ -0,0 +1,39 @@
+"""粉尘阈值 / 卖回封顶 / 买入增量逻辑相关单测."""
+from __future__ import annotations
+
+import unittest
+
+from lib.options.options_spot_bridge_lib import (
+    display_sellable_coin,
+    is_sellable_spot_coin,
+    spot_min_sell_sz,
+)
+
+
+class TestSpotDust(unittest.TestCase):
+    def test_min_sz_fallback(self):
+        self.assertAlmostEqual(spot_min_sell_sz(None, "ETH"), 0.0001)
+        self.assertAlmostEqual(spot_min_sell_sz(None, "BTC"), 0.00001)
+
+    def test_dust_not_sellable(self):
+        self.assertFalse(is_sellable_spot_coin(None, "ETH", 0.000004))
+        self.assertFalse(is_sellable_spot_coin(None, "BTC", 0.000002))
+        self.assertEqual(display_sellable_coin(None, "ETH", 0.000004), 0.0)
+
+    def test_above_min_sellable(self):
+        self.assertTrue(is_sellable_spot_coin(None, "ETH", 0.0001))
+        self.assertTrue(is_sellable_spot_coin(None, "BTC", 0.00001))
+        self.assertGreater(display_sellable_coin(None, "ETH", 0.001), 0)
+
+
+class TestSellCapLogic(unittest.TestCase):
+    def test_excess_cap_math(self):
+        bought, keep = 0.01, 0.004
+        excess = max(0.0, bought - keep)
+        self.assertAlmostEqual(excess, 0.006)
+        sell_amt = min(0.02, excess)
+        self.assertAlmostEqual(sell_amt, 0.006)
+
+
+if __name__ == "__main__":
+    unittest.main()