fix(frontend): 修复新手引导中Select下拉框无法点击的问题

- 使用 Teleport 将 Select 下拉菜单渲染到 body，避免 driver.js 遮罩层阻挡
- 添加 pointer-events 和 @click.stop 确保下拉选项可点击
- 移除 useOnboardingTour 中无效的 Select 组件处理代码
- 清理未使用的 CSS 样式和 console 调试语句
- 简化 Select 组件在引导期间的交互逻辑

frontend/src/components/layout/AppLayout.vue

@@ -25,23 +25,19 @@
 <script setup lang="ts">
 import '@/styles/onboarding.css'
 import { computed, onMounted } from 'vue'
-import { useI18n } from 'vue-i18n'
 import { useAppStore } from '@/stores'
 import { useAuthStore } from '@/stores/auth'
 import { useOnboardingTour } from '@/composables/useOnboardingTour'
-import { getAdminSteps, getUserSteps } from '@/components/Guide/steps'
 import { useOnboardingStore } from '@/stores/onboarding'
 import AppSidebar from './AppSidebar.vue'
 import AppHeader from './AppHeader.vue'
 
 const appStore = useAppStore()
 const authStore = useAuthStore()
-const { t } = useI18n()
 const sidebarCollapsed = computed(() => appStore.sidebarCollapsed)
 const isAdmin = computed(() => authStore.user?.role === 'admin')
 
 const { replayTour } = useOnboardingTour({
-  steps: isAdmin.value ? getAdminSteps(t) : getUserSteps(t),
   storageKey: isAdmin.value ? 'admin_guide' : 'user_guide',
   autoStart: true
 })