Replace engine._model/engine._generation_config mocks with engine._client/engine._model_name. Update sys.modules patches from vertexai to google.genai. Remove dead if-False branch. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Replace engine._model/engine._generation_config mocks with engine._client/engine._model_name. Update sys.modules patches from vertexai to google.genai. Remove dead if-False branch. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>