feat(freight-backoffice): rework settings pages for the per-currency API

exchangeSettings.service/hook/card follow the backend's new shape: a
single ExchangeSettings object becomes a list, get() becomes list(),
and setFallbackRate(rate) becomes setFallbackRate(currency, rate).
ExchangeRateSettingsCard now renders one row per currency instead of
one hardcoded USD->ETB form.

manualPaymentSettings.service/hook/card add djfEnabled alongside
etb/usdEnabled, matching the backend's new column.

InvoicesPage's collected-summary KPI strip adds a DJF tile and folds
its ETB-equivalent into the existing 'Total collected' conversion,
reading each currency's rate from the now-list-shaped settings query.

Claude-Session: https://claude.ai/code/session_01CZy77vCWhka3pnmVF9NDkL

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

@@ -7,10 +7,11 @@ import { useErrorHandler } from "@/shared/hooks/useErrorHandler";
 
 const QUERY_KEY = ["exchangeSettings"];
 
+/** One row per foreign currency (USD, DJF, …) — see `exchangeSettingsService.list`. */
 export const useExchangeSettingsQuery = () =>
   useQuery({
     queryKey: QUERY_KEY,
-    queryFn: () => exchangeSettingsService.get(),
+    queryFn: () => exchangeSettingsService.list(),
     // Feed health is only interesting while it is being looked at.
     staleTime: 30_000,
     refetchOnWindowFocus: true,
@@ -22,7 +23,8 @@ export const useSetExchangeFallbackRate = () => {
   const { handleError } = useErrorHandler(t);
 
   return useMutation({
-    mutationFn: (rate: number) => exchangeSettingsService.setFallbackRate(rate),
+    mutationFn: ({ currency, rate }: { currency: string; rate: number }) =>
+      exchangeSettingsService.setFallbackRate(currency, rate),
     onSuccess: () => {
       queryClient.invalidateQueries({ queryKey: QUERY_KEY });
       toast.success(

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

@@ -24,7 +24,9 @@ export const useUpdateManualPaymentSettings = () => {
 
   return useMutation({
     mutationFn: (
-      patch: Partial<Pick<ManualPaymentSettings, "etbEnabled" | "usdEnabled">>,
+      patch: Partial<
+        Pick<ManualPaymentSettings, "etbEnabled" | "usdEnabled" | "djfEnabled">
+      >,
     ) => manualPaymentSettingsService.update(patch),
     onSuccess: (data) => {
       queryClient.setQueryData(MANUAL_PAYMENT_SETTINGS_KEY, data);