Canon: enforce reporter idempotency and record PASS evidence

[andreidita22]

Summary

• ensure reporterWrite skips appending log entries that already exist in the artifact
• extend the idempotent invariant coverage to guard against repeats across interleaved writes
• capture the Canon PASS artifacts and implementation report for submission

Testing

• .codex/selfcheck.sh runs/canon-loop-demo/meta/compose.json amr/canon.lock.json modules
• node tm.mjs gates shipping --compose runs/canon-loop-demo/meta/compose.json --modules-root modules --emit-events --strict-events

---

https://chatgpt.com/codex/tasks/task_e_68f44dfe59248320a19f272e7edb3ab8

[gemini-code-assist]

Summary of Changes

Hello @andreidita22, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request significantly improves the robustness of the reporterWrite function by implementing a more comprehensive idempotency check. it ensures that log entries are not duplicated, even when multiple write attempts occur or when other messages are interleaved. Furthermore, it introduces the generation of critical artifacts, events.ndjson and implementation_report.json, upon successful Canon runs. These artifacts provide detailed evidence of system behavior and test outcomes, enhancing the overall reliability and auditability of the reporting process.

Highlights

• Enhanced Reporter Idempotency: The reporterWrite function now prevents duplicate log entries by checking against all prior entries, not just the last one, using a Set for efficient lookup.
• Interleaved Write Protection: The idempotency logic has been extended to correctly handle scenarios where other log entries are written between attempts to write the same message, ensuring the message is still only recorded once.
• Canon PASS Artifacts & Report: The system now captures and generates events.ndjson (event logs) and implementation_report.json (a structured report of test results and evidence) for successful Canon runs, improving traceability and verification.

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[gemini-code-assist]

Code Review

This pull request correctly strengthens the idempotency of reporterWrite by ensuring duplicate messages are not appended, even with interleaved writes. The changes to the implementation and the corresponding test updates are logical and improve the robustness of the reporter. I've identified a potential performance concern in reporterWrite due to reading the entire log file on each call, and a minor code inconsistency in the test runner. Overall, these are solid improvements.

[gemini-code-assist]

This new logic correctly ensures idempotency by checking the entire log history. However, it's worth noting that this approach, which relies on reading the full log file and creating a Set on every reporterWrite call, could introduce a performance bottleneck if the log files become very large. While this is acceptable for now, it's a trade-off to keep in mind for future scaling.

[gemini-code-assist]

To maintain consistency with the normalizeLines function in modules/reporter/src/index.js, it's better to use .trimEnd() here instead of .trim(). While it may not affect the outcome of this specific test because input messages are trimmed, aligning the logic prevents potential future discrepancies and improves code consistency.

Suggested change

	.map((line) => line.trim())
	.map((line) => line.trimEnd())