feat: add daily tasks and fix /admin139 admin entry

frontend/src/app/admin139/page.tsx

@@ -0,0 +1,28 @@
+import Link from "next/link";
+
+export default function AdminEntryPage() {
+  return (
+    <main className="mx-auto max-w-3xl px-4 py-10">
+      <h1 className="text-2xl font-semibold">后台管理入口</h1>
+      <p className="mt-3 text-sm text-zinc-600">
+        默认管理员账号：<span className="font-medium text-zinc-900">admin</span>，密码：
+        <span className="font-medium text-zinc-900">whoami139</span>
+      </p>
+
+      <div className="mt-6 grid gap-3 sm:grid-cols-2">
+        <Link className="rounded-lg border bg-white px-4 py-3 text-sm hover:bg-zinc-50" href="/auth">
+          去登录
+        </Link>
+        <Link className="rounded-lg border bg-white px-4 py-3 text-sm hover:bg-zinc-50" href="/admin-users">
+          用户积分管理
+        </Link>
+        <Link className="rounded-lg border bg-white px-4 py-3 text-sm hover:bg-zinc-50" href="/admin-redeem">
+          积分兑换管理
+        </Link>
+        <Link className="rounded-lg border bg-white px-4 py-3 text-sm hover:bg-zinc-50" href="/backend-logs">
+          后台任务日志
+        </Link>
+      </div>
+    </main>
+  );
+}