feat: brand dodo loading screen

frontend/src/App.vue

@@ -1300,7 +1300,7 @@ onUnmounted(() => {
 </script>
 
 <template>
-  <div v-if="!authReady" class="center"><span class="loader" />正在打开 dodo…</div>
+  <div v-if="!authReady" class="center loading-brand"><img class="loading-logo" src="/dodo-logo.svg" alt=""><span class="loader" /><span>正在打开 dodo…</span></div>
   <div v-else-if="!authenticated" class="auth-shell">
     <section class="auth-card">
       <div class="brand brand-lockup"><img class="brand-logo" src="/dodo-logo.svg" alt=""><span class="brand-wordmark">dodo</span></div><p>{{ initialized ? '欢迎回来，继续把生活理顺。' : '创建你的 dodo' }}</p>

frontend/src/style.test.ts

@@ -1102,7 +1102,11 @@ describe('sidebar information hierarchy', () => {
     expect(css).toContain('.brand-row{height:64px;')
     expect(app).toContain('class="brand brand-lockup"')
     expect(app).toContain('class="brand small brand-lockup"')
-    expect(app.match(/src="\/dodo-logo\.svg"/g)).toHaveLength(2)
+    expect(app).toContain('class="center loading-brand"')
+    expect(app).toContain('class="loading-logo"')
+    expect(app.match(/src="\/dodo-logo\.svg"/g)).toHaveLength(3)
+    expect(css).toContain('.loading-brand{grid-template-columns:auto;justify-items:center;gap:13px}')
+    expect(css).toContain('.loading-logo{width:40px;height:40px;')
     expect(css).toContain('.brand-logo{width:42px;height:42px;')
     expect(css).toContain('.brand.small .brand-logo{width:32px;height:32px}')
     expect(css).not.toContain('.brand span{color:var(--accent)}')