Resume with collapsed revision groups was untested: the resume point is
the (articleid, revid) of the last written row, which for collapsed
output is the last revision of a group, and nothing verified that the
replay reconstructs group boundaries and collapsed_revs counts
identically across the resume point. Run sailormoon with
--collapse-user, truncate the output at the midpoint, resume, and
assert the result is identical to an uninterrupted run.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
(cherry picked from commit 6634de51e6)
