Page-status readout: renders "Page n of m" for the current page. Pure
derivation from the host pageIndex()/totalPages() signals - no local
state, no writes. It is the visible counterpart of the
announcements.pageChange live-region phrasing, and the collapse target the
responsive number row swaps to once the paginator's container narrows. Text
comes from the config pageStatus formatter, so it localises with the rest of
the cascade; tabular figures keep the numerals from reflowing as the page
changes.