refactor(layout): 重构基础布局头部组件结构

src/layouts/base-layout/base-layout-header/components/LanguageSwitchButton.vue

@@ -0,0 +1,33 @@
+<script setup lang="ts">
+import type { DropdownOption } from 'naive-ui';
+
+const { locale, availableLocales } = useI18n({ useScope: 'global' });
+
+const languageLabels: Record<string, string> = {
+  'en-US': 'English',
+  'zh-CN': '简体中文',
+};
+
+const options = computed<DropdownOption[]>(() =>
+  availableLocales.map((lang) => ({
+    label: languageLabels[lang] || lang,
+    key: lang,
+    disabled: locale.value === lang,
+  })),
+);
+
+function handleSelect(key: string) {
+  locale.value = key;
+}
+</script>
+
+<template>
+  <NDropdown trigger="hover" placement="bottom-end" :options="options" @select="handleSelect">
+    <NButton quaternary class="flex items-center gap-1">
+      <template #icon>
+        <icon-clarity:language-line w-4.5 h-4.5 />
+      </template>
+      <span>{{ languageLabels[locale] }}</span>
+    </NButton>
+  </NDropdown>
+</template>