Add delivery notes

Author: aitoruriapersonal

NOTES.md

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+I approved a small plan focused on the existing users route and the in-memory store. The plan was to confirm the failing tests first, add a store-level update helper so the route keeps using db/store.js for data access, then implement PUT /users/:id with the same validation style as POST and explicit 404 handling for a missing user. I did not need to broaden the plan beyond that, but I made the validation order explicit so a missing field returns 400 before any update attempt.
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+I used GPT-5.4 for this task because the change is small but still benefits from tight test-driven iteration and careful handling of edge cases like missing fields and unknown ids.
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+I split the work into two logical commits: one for the feature itself in the route and store, and one for the delivery notes after the implementation was green. That keeps the behavior change separate from the required write-up.
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+My review was focused on the not-found path, the validation path, and whether the route still goes through db/store.js instead of mutating state directly. The review did not surface any extra bugs; it mainly confirmed that the endpoint returns 200, 400, and 404 in the cases covered by the tests.