synthetic-not-pi._expectations.md (synthetic)
All files are synthetic, not native session extracts. V17 rejects a non-Pi format whose first record is not a session header.
Scenario and expectations
- First line {“type”:“event_msg”,…} resembles Codex rollout. Even a valid session header on line 2 does not qualify; detection checks the first line only.
- detect=UnknownFormat(“first record type is not session header”).
- Run: status=unknown_format, no events, one unknown_format diagnostic; source_files.status=unsupported.