Fix nitrogen allocation to litter pool during harvest events (#244)

[Thomas-Sedhom]

Summary

This PR fixes nitrogen loss during harvest events.

Currently, harvest transfers carbon from plant biomass to the litter pool but does not allocate the associated nitrogen. Since plant nitrogen is not explicitly tracked in SIPNET, this results in nitrogen being lost from the system.

Related issues

Fixes #244

Checklist

• Related issues are listed above. PRs without an approved, related issue may not get reviewed.
• PR title has the issue number in it ("[#] <concise description of proposed change>")
• Tests added/updated for new features (if applicable)
• Documentation updated (if applicable)
• docs/CHANGELOG.md updated with noteworthy changes
• Code formatted with clang-format (run git clang-format if needed)

---

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[Alomir]

Looks great so far. This should break a unit test, but is unlikely to before we update them (future work, though very-soon future work). I suspect the russell_2 smoke test will fail.

Please resolve the conflicts in events.c and we'll see how it goes.

[Alomir]

In the PR summary, the related issue needs to be

- Fixes #244

not an embedded link. Github will take care of the linking, as well as automagically assigning this PR as closing that ticket.

[Thomas-Sedhom]

If everything looks good, I can start working on fixing the russell_2 smoke test next.

[Alomir]

@Thomas-Sedhom One thing - please make sure the code builds cleanly locally before pushing changes.

[Alomir]

Hey @Thomas-Sedhom - to be clear, we don't have any harvest events in the smoke tests (yet!), so we won't see any break.

[Alomir]

Looks great - just one missed rename that needs to be done.

[Thomas-Sedhom]

Hey @Thomas-Sedhom - to be clear, we don't have any harvest events in the smoke tests (yet!), so we won't see any break.

Thanks for clarifying! That makes sense.

[Alomir]

Looks good, nice job!

[Alomir]

Whoops, tests are failing - can't wait until the B&T runs automatically.

[Alomir]

All good now