rekey_rotates_owner_share_and_keeps_listed_recipients failed in CI:
the response's wrapped_profile_dek was 'owner-dek-v1' (old) instead of
'owner-dek-v2' (new). update_wrapped_dek uses find_one_and_update,
which returns the document as it was BEFORE the update by default —
so reading the new value from the returned doc gives the pre-image.
Fix: echo the request values (exactly what was stored) in the response
instead of reading them back. Unambiguous and avoids the
ReturnDocument::After plumbing. The write itself was always correct
(the stored value was v2) — only the response was stale, which is why
the other rekey tests (which check state via fresh reads, not the
response body) passed.
Now CI-green (clippy/fmt clean; integration tests will re-run).
6d6af67f2f