implement logout dialog, fix unused imports

src/components/ui/dialog/DialogHeader.vue

@@ -0,0 +1,14 @@
+<script setup lang="ts">
+import { cn } from '@/lib/utils'
+import type { HTMLAttributes } from 'vue'
+
+const props = defineProps<{
+  class?: HTMLAttributes['class']
+}>()
+</script>
+
+<template>
+  <div :class="cn('flex flex-col space-y-1.5 text-center sm:text-left', props.class)">
+    <slot />
+  </div>
+</template>