Five copies of formatRelativeTime had drifted across apps/web into three
different output vocabularies, so the same timestamp read differently
depending on which surface rendered it. lib/utils.ts is now the single
implementation.
Deletes the private copies in task-item, automations/format-utils,
commit-detail-panel, and kanban/graph2-task-pipeline; commit-detail-panel
adopts the shared short form rather than keeping its long-form wording.
Adds bucket-boundary unit tests for the shared function.
Carlos Florêncio