Don't Golden-File an Agent Patch. Golden-File the Relation.

<p>A patch touches zero test files. No assertion changes, no new skips, no fixture edits. The suite goes green on the first run.</p> <p>Then someone opens the job duration graph

<p>Same-session tests are not evidence. If an agent writes a production hunk and the assertions in one pass, a green build often means the two files agreed on a private story, not

<p>An agent patch that passes its own tests is a baseline, not a verdict. The same model wrote the code and the tests, so both share the same blind spots. Mutation testing scores

<p>Deterministic agent tests become much more valuable when they are expressed as reusable quality gates rather than one-off assertions scattered across test files.</p> <p>A gate