Replace the local-vs-UTC test with a timestamp that actually straddles UTC
day boundary (00:30 local on 2 September = 22:30Z on the 1st). The original
test was vacuous because both readings agreed on the same calendar day.
Delete the rename-stability test which was a tautology — occurrenceId never
takes a title, so any pure function satisfied it. The real assertion belongs
in a later task where the whole rule is passed in and a rename can be
exercised.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>