UAT round 3 feedback on the card layout:
- Add a pager + "Cards per page" to the card view (it infinitely-scrolled before).
Extracted the pager cluster out of DataTable into a reusable Pager component
(the table now renders it too — no behaviour change); the card view slices the
sorted rows and drives its own per-account page size (subscribed + discovery).
- Restore the top edge-fade in the card layout. The channels page registers
fadeTop:false for its sticky-header table; the card layout has no sticky header,
so App now re-enables the top fade when the channel layout is cards.