feat(config): default to WebSocket and migrate saved HTTP settings

tests/unit/test_model_proxy.py

@@ -17,7 +17,7 @@ async def test_sync_and_async_clients_follow_env_only_proxy_policy(monkeypatch,
     monkeypatch.delenv("ARTEMIS_FAKE_LLM", raising=False)
     monkeypatch.setattr(settings, "OPENAI_USE_SYSTEM_PROXY", use_proxy)
     model = ModelFactory.create_model(
-        ModelEndpoint(api_key="test-only", api_base="https://example.invalid/v1")
+        ModelEndpoint(api_key="test-only", api_base="https://example.invalid/v1", transport="http")
     )
     try:
         for client in (model.http_client, model.http_async_client):