test: add pytest markers to existing test classes

tests/test_google_api_key.py

@@ -1,9 +1,12 @@
 import unittest
 from unittest.mock import patch
 
+import pytest
+
 from tradingagents.llm_clients.google_client import GoogleClient
 
 
+@pytest.mark.unit
 class TestGoogleApiKeyStandardization(unittest.TestCase):
     """Verify GoogleClient accepts unified api_key parameter."""
 

tests/test_model_validation.py

@@ -1,6 +1,8 @@
 import unittest
 import warnings
 
+import pytest
+
 from tradingagents.llm_clients.base_client import BaseLLMClient
 from tradingagents.llm_clients.model_catalog import get_known_models
 from tradingagents.llm_clients.validators import validate_model
@@ -19,6 +21,7 @@ class DummyLLMClient(BaseLLMClient):
         return validate_model(self.provider, self.model)
 
 
+@pytest.mark.unit
 class ModelValidationTests(unittest.TestCase):
     def test_cli_catalog_models_are_all_validator_approved(self):
         for provider, models in get_known_models().items():

tests/test_ticker_symbol_handling.py

@@ -1,9 +1,12 @@
 import unittest
 
+import pytest
+
 from cli.utils import normalize_ticker_symbol
 from tradingagents.agents.utils.agent_utils import build_instrument_context
 
 
+@pytest.mark.unit
 class TickerSymbolHandlingTests(unittest.TestCase):
     def test_normalize_ticker_symbol_preserves_exchange_suffix(self):
         self.assertEqual(normalize_ticker_symbol(" cnc.to "), "CNC.TO")