Add self-review confirmation to the PR checklist

[dblythy]

New Feature / Enhancement Checklist

• Report security issues confidentially.
• Any contribution is under this license.
• Before posting search existing issues.

Current Limitation

The Tasks checklist in the PR template covers tests, docs, security checks and error codes, but nothing asks authors to confirm they've reviewed and understood their own change. With AI agents producing more of the code in PRs, it's become easy to submit a working-looking change the author can't actually explain, which shifts the whole comprehension burden onto reviewers.

Feature / Enhancement Description

Add a self-review item to the Tasks checklist in .github/pull_request_template.md, something like:

- [ ] I have reviewed this PR line by line and understand how the change works and why it is correct

Exact wording open for discussion - the point is that ticking it is the author signing that the PR isn't unreviewed AI output.

Example Use Case

1. An author (or their coding agent) prepares a change
2. Before opening the PR, the author reads the diff and makes sure they can explain it
3. They tick the checkbox
4. Reviewers can ask the author to walk through any part of the change, and the checkbox sets that expectation up front

Alternatives / Workarounds

Reviewers asking authors to explain their changes case by case. Works, but sets no expectation up front and usually happens after review time has already been spent.

3rd Party References

Projects like curl and QEMU have introduced contribution policies requiring authors to disclose AI assistance and vouch that they understand and verified what they're submitting.

[parse-github-assistant]

🚀 Thanks for opening this issue! We are excited about your ideas for improvement!

[mtrezza]

Checkboxes are ineffective gates for humans - either they're ignored or blindly checked. We are already posting a rule summary on every PR. However, when rules are ignored or rejected by contributors, even as they are plainly pointed out to them, then no summary or checkbox will help. The only remediation is enforcement after the fact. From de-prioritizing submissions by users who submit low-quality PRs, up to blocking them.

[dblythy]

Hmm fair enough, I do think the template more broadly has some value, even if that's diminishing when it's likely to be filled out by AI. The rule summary comes after the fact and I do think there's some value setting the expectations of contributors to be around what their contribution is.

The checkbox isn't really meant to stop anyone though - it's the author signing that they understand the change, which makes the enforcement you mention quicker