Replace the minimal placeholder Toaster with the richer implementation
already built on compliance-portal-auth (per-type icons plus warning and
info variants, and its stories). Both branches now share the exact same
component and app-root wiring, so they converge instead of colliding
when they merge. Align App.tsx provider ordering to match.
Signed-off-by: Émile Ré <emile@probo.com>