An agent patch is only as trustworthy as the checks it cannot rewrite. If properties, fixtures, and flake policy live in the same tree as src/, the diff can weaken the proof. Move the oracle out of the writable tree and run it as a control loop with hysteresis, not as a skip list.
Co-located tests fail this requirement in a predictable way. The agent adds an assertion that matches the new code. A fixture grows a default that hides a broken parser. A flaky case becomes skip. The suite stays green. Production still drifts.
This article proposes a sidecar oracle: human-owned properties, sealed fixtures, and a two-threshold flake freeze. The design is a workflow, not a production case study. Treat the code as a proposed runner you can execute locally, not as a claim about a live fleet.
What the loop decides
The loop answers three questions on every candidate patch:
