fix: leave setup wizard after completion

frontend/src/pages/setup/index.vue

@@ -378,19 +378,18 @@ function confirmSetup() {
 function startCountdown() {
   window.clearInterval(countdownTimer);
   countdownTimer = window.setInterval(() => {
-    countdown.value -= 1;
-    if (countdown.value <= 0) void openLogin();
+    countdown.value = Math.max(0, countdown.value - 1);
+    if (countdown.value === 0) openLogin();
   }, 1000);
 }
 
-async function openLogin() {
+function openLogin() {
   window.clearInterval(countdownTimer);
-  completionMessage.value = '系统正在启动，请稍候。';
-  if (await waitForSetupCompletion()) {
-    await router.replace('/login');
-    return;
-  }
-  completionMessage.value = '系统启动时间较长，请稍后刷新页面。';
+  countdown.value = 0;
+  completionMessage.value = '正在进入登录页。';
+  // A full navigation clears the setup-mode SPA state retained across the
+  // service restart. The login route guard performs the final setup check.
+  window.location.replace('/login');
 }
 
 onMounted(async () => {