feat: implement ModalFooter component for consistent modal action layout

apps/backoffice/src/app/features/payment-config/pages/PaymentConfigPage.tsx

@@ -26,7 +26,7 @@ import {
   IconInfoCircle,
   IconLock,
 } from '@tabler/icons-react';
-import { notify } from '@ema-platform/ui';
+import { notify, ModalFooter } from '@ema-platform/ui';
 import {
   extractErrorMessage,
   localized,
@@ -364,14 +364,14 @@ function FeeEditModal({
             </>
           )}
 
-          <Group justify="flex-end" mt="xs">
+          <ModalFooter mt="xs">
             <Button variant="default" onClick={onClose} disabled={isLoading}>
               Cancel
             </Button>
             <Button onClick={save} loading={isLoading}>
               Save fees
             </Button>
-          </Group>
+          </ModalFooter>
         </Stack>
       )}
     </Modal>