/admin redirected to the invoice list, which stopped making sense once
the admin also ran the bingo. Make it a dashboard with one tile per
area: invoice totals, outstanding amount per currency, overdue count and
the five latest invoices; the bingo score, reserve size, latest incident
and card cells still missing a photo. A shared nav links the sections.
Tiles are per area so they can follow user permissions later.
Assisted-by: Claude:opus-5
