## Summary - add a reusable `ev_response_created` helper that builds `response.created` SSE events for integration tests - update the exec and core integration suites to use the new helper instead of repeating manual JSON literals - keep the streaming fixtures consistent by relying on the shared helper in every touched test ## Testing - `just fmt` ------ https://chatgpt.com/codex/tasks/task_i_68e1fe885bb883208aafffb94218da61