fix: avoid worker fetch noise when server is offline

tests/test_api.py

@@ -3,6 +3,7 @@ Test API endpoints
 """
 
 import pytest
+import requests
 from unittest.mock import patch, MagicMock
 
 def test_health_check(client):
@@ -107,10 +108,21 @@ def test_get_running_models_ollama_offline(client):
 def test_get_models_ollama_offline(client):
     """Test getting models when Ollama is offline"""
     with patch("requests.get") as mock_get:
-        mock_get.side_effect = Exception("Connection refused")
+        mock_get.side_effect = requests.exceptions.ConnectionError("Connection refused")
         
         response = client.get("/api/v1/models")
-        assert response.status_code == 500
+        assert response.status_code == 502
+
+
+def test_get_models_returns_502_when_upstream_is_unavailable(client):
+    """Non-200 upstream response should remain a 502, not be converted to 500."""
+    with patch("requests.get") as mock_get:
+        mock_response = MagicMock()
+        mock_response.status_code = 503
+        mock_get.return_value = mock_response
+
+        response = client.get("/api/v1/models")
+        assert response.status_code == 502
 
 def test_get_specific_model(client, mock_models_response):
     """Test getting specific model"""