- F2: handleApproveOperation now runs tryApproveOperation inside
RunInTransaction with CAS guard on (ApprovedBy, Status). Two
concurrent final-approvers can no longer both satisfy quorum and
both trigger signing; exactly one wins, the other retries or sees
"operation not in pending_approval state". 5 retries with backoff,
then 409 conflict.
- F23: initiator can NEVER self-approve, regardless of how many
approvals already exist. Previous code only blocked self-approval
when len(ApprovedBy) == 0.
- F10: list handlers (operations + audit) now call Count() on the
filtered query before fetching the page; totalItems reflects the
real count, not len(page). Added page/perPage response fields.
- F20: operation status filter is validated against the spec enum
(pending_approval, approved, signed, rejected, failed, expired).
Unknown values return 400 instead of silently dropping the filter.