修正期权开仓 51008 文案：不再误报资金账户 USDT，按 USDC/USDT 区分提示。

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

tests/test_okx_spot_swap.py

@@ -37,9 +37,24 @@ class TestOkxSpotSwap(unittest.TestCase):
         )
         result = spot_market_swap_usdt_usdc(ex, direction="usdt_to_usdc", amount=20)
         self.assertFalse(result["ok"])
-        self.assertEqual(result["msg"], "资金账户 USDT 可用余额不足")
+        self.assertEqual(result["msg"], "USDT 可用余额不足(期权请先兑成 USDC 并划入交易账户)")
         self.assertNotIn("{", result["msg"])
 
+    def test_insufficient_usdc_message(self):
+        from lib.exchange.okx_options_lib import _okx_trade_error_message
+
+        msg = _okx_trade_error_message(
+            resp={
+                "data": [
+                    {
+                        "sCode": "51008",
+                        "sMsg": "Order failed. Insufficient USDC balance in account.",
+                    }
+                ]
+            }
+        )
+        self.assertEqual(msg, "交易账户 USDC 可用余额不足")
+
 
 if __name__ == "__main__":
     unittest.main()