feat(overview): resolve dashboard layout from permissions, not role keys

role-dashboards.config.ts's ROLE_LAYOUTS was a hand-typed table of ~40
raw role/position keys (including edr_freight_app/xxx ad-hoc
sub-positions), matched against the user's held keys client-side.
Replaced with resolveOverviewLayout(), which just picks the
highest-priority key out of whatever GET /overview/layouts returns —
the same 'server filters by permission, frontend renders what comes
back' shape Reports already uses, so the frontend no longer needs to
know any individual permission key.

Hard cutover: no fallback to the old key table. Positions not covered
by the previous commit's grants (the ad-hoc department sub-positions)
will render the executive layout until granted a layout permission.

apps/edr-freight-web/backoffice/src/hooks/useOverview.ts

@@ -11,6 +11,15 @@ export function useOverview(range: OverviewRange = "30d") {
   });
 }
 
+/** Layouts the caller may render — server-filtered by permission, same shape as useReports' catalog. */
+export function useOverviewLayouts() {
+  return useQuery({
+    queryKey: QUERY_KEYS.OVERVIEW.layouts(),
+    queryFn: () => overviewService.getLayouts(),
+    staleTime: 5 * 60 * 1000,
+  });
+}
+
 export function useOverviewBookingsTab(range: OverviewRange, enabled: boolean) {
   return useQuery({
     queryKey: QUERY_KEYS.OVERVIEW.bookingsTab(range),