Reapply "Add missing admin action files and navigation links"

This reverts commit 4d515bc400.

src/app/staff/page.tsx

@@ -82,9 +82,7 @@ export default async function StaffPage() {
         icon="👥"
         title={t("membersTitle")}
         subtitle={
-          staff.length === 0
-            ? t("membersEmptySubtitle")
-            : t("membersSubtitle", { count: staff.length })
+          staff.length === 0 ? t("membersEmptySubtitle") : t("membersSubtitle", { count: staff.length })
         }
         padded={staff.length === 0}
       >