- Render each hunk action as a DropdownMenuItem (Stage/Unstage/Discard hunk N
with +/- counts) so Base UI keyboard navigation, highlight, Escape, and
close-on-activate apply. Plain div/button rows are gone.
- Row labels reuse the already-translated diffView.hunk.stageTitle /
unstageTitle / discardTitle strings; no new i18n keys, no hardcoded English.
- Disable the file-level actions while a hunk action is in flight for
consistency (server serializes per directory regardless).