Fix test_get_providers mock to match actual API response format

The OpenRouter endpoints API returns { data: { endpoints: [...] } } with
provider_name fields, not the flat array the test was mocking.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: DevStrategist

llm-benchmark/tests/test_clients.py

@@ -51,21 +51,24 @@ async def test_get_models(self, client):
     async def test_get_providers(self, client):
         mock_response = MagicMock()
         mock_response.json.return_value = {
-            "data": [
-                {"id": "together", "name": "Together", "order": 0, "is_moderated": False},
-                {"id": "openai", "name": "OpenAI", "order": 1, "is_moderated": True}
-            ]
+            "data": {
+                "endpoints": [
+                    {"provider_name": "Together"},
+                    {"provider_name": "OpenAI"}
+                ]
+            }
         }
         mock_response.raise_for_status = MagicMock()
-        
+
         with patch.object(client.client, 'get', return_value=mock_response) as mock_get:
             providers = await client.get_providers("openai/gpt-4")
-            
+
             assert len(providers) == 2
-            assert providers[0].id == "together"
+            assert providers[0].name == "Together"
             assert providers[0].order == 0
-            assert providers[1].is_moderated == True
-            
+            assert providers[1].name == "OpenAI"
+            assert providers[1].order == 1
+
             mock_get.assert_called_once()
             assert "openai/gpt-4/endpoints" in mock_get.call_args[0][0]