fix: avoid login flash during session restore

frontend/src/App.vue

@@ -18,6 +18,7 @@ type Task = { id: string; list_id: string; parent_id: string | null; title: stri
 type View = 'tasks' | 'today' | 'upcoming' | 'trash' | 'habits' | 'calendar' | 'settings'
 
 const initialized = ref<boolean | null>(null)
+const authReady = ref(false)
 const authenticated = ref(false)
 const username = ref('')
 const password = ref('')
@@ -111,6 +112,7 @@ function toast(message: string) {
 function fail(reason: unknown) { error.value = reason instanceof Error ? reason.message : '请求失败' }
 
 async function bootstrap() {
+  authReady.value = false
   try {
     const status = await api('/setup/status')
     initialized.value = status.initialized
@@ -125,7 +127,12 @@ async function bootstrap() {
       expandedFolders.value = new Set(folders.value.map((folder) => folder.id))
       await loadAll()
     }
-  } catch { authenticated.value = false; initialized.value ??= true }
+  } catch {
+    authenticated.value = false
+    initialized.value ??= true
+  } finally {
+    authReady.value = true
+  }
 }
 async function submitAuth() {
   error.value = ''
@@ -382,7 +389,7 @@ onMounted(bootstrap)
 </script>
 
 <template>
-  <div v-if="initialized === null" class="center"><span class="loader" />正在打开 dodo…</div>
+  <div v-if="!authReady" class="center"><span class="loader" />正在打开 dodo…</div>
   <div v-else-if="!authenticated" class="auth-shell">
     <section class="auth-card">
       <div class="brand">do<span>do</span></div><p>{{ initialized ? '欢迎回来，继续把生活理顺。' : '创建你的 dodo' }}</p>