More robust PR template and contributing guidelines

[kennethshsu]

Summary of Changes

Improved the contribution guidelines and the PR template

Related GitHub Issue(s)

N/A

Additional Context for Reviewers

To better protect the quality of work of this package, I'd like to propose we put a few more guardrails on PRs so that anyone looking at this package knows there's a certain level of quality that is expected.

The CAS Primer says that we should have a human in the loop and discloses AI tools used.

The code says only Qualified actuarial on the with basis of basic, continuing ed, and experience met shall perform actuarial services. I think we should ask pull requests to make a self declaration if that's not the case.

There's also a bunch more relevant ASOPs that I skimmed through, like ASOP 23 Data Quality, ASOP 41 on Actuarial Communications, and ASOP 56 on Modeling that we should all consider, but I don't think it's necessary to bring them all in as a checklist in the PR template.

Anyway, this is coming in as a PR, and I don't want to just introduce red tape, I'm also not married to these at all. Open to discussion.

• I passed tests locally for both code (uv run pytest) and documentation changes (uv run jb build docs --builder=custom --custom-builder=doctest)

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Note

Low Risk
Low risk documentation-only change that updates contributor guidance and PR requirements; main impact is on contributor workflow/expectations, not runtime behavior.

Overview
Updates the PR template to add guidance comments and a new checklist requiring local test runs, AI usage disclosure, and contributor attestations (including CAS credential disclosure when applicable).

Tightens docs/library/contributing.md PR guidelines by explicitly requiring use of the PR template, disclosure of AI coding agents, and qualified actuarial peer review, and updates the test command example to uv run pytest.

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[kennethshsu]

@genedan @henrydingliu @jbogaardt please share your thoughts, also open to everyone watching this thread.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.40%. Comparing base (7f53616) to head (a60a95a).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #827   +/-   ##
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  Coverage   86.40%   86.40%           
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  Files          86       86           
  Lines        4959     4959           
  Branches      642      642           
=======================================
  Hits         4285     4285           
  Misses        478      478           
  Partials      196      196           

Flag	Coverage Δ
unittests	86.40% <ø> (ø)

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