feat(frontend): 优化弹窗组件架构和用户体验

- 使用 BaseDialog 替代旧版 Modal 组件
- 添加平滑过渡动画和更好的可访问性支持
- 新增 ExportProgressDialog 导出进度弹窗
- 优化所有账号管理和使用记录相关弹窗
- 更新国际化文案，改进用户交互体验
- 精简依赖，减少 package.json 体积

frontend/src/components/common/ExportProgressDialog.vue

@@ -0,0 +1,68 @@
+<template>
+  <BaseDialog :show="show" :title="t('usage.exporting')" width="narrow" @close="handleCancel">
+    <div class="space-y-4">
+      <div class="text-sm text-gray-600 dark:text-gray-400">
+        {{ t('usage.exportingProgress') }}
+      </div>
+      <div class="flex items-center justify-between text-sm text-gray-700 dark:text-gray-300">
+        <span>{{ t('usage.exportedCount', { current, total }) }}</span>
+        <span class="font-medium text-gray-900 dark:text-white">{{ normalizedProgress }}%</span>
+      </div>
+      <div class="h-2 w-full rounded-full bg-gray-200 dark:bg-dark-700">
+        <div
+          role="progressbar"
+          :aria-valuenow="normalizedProgress"
+          aria-valuemin="0"
+          aria-valuemax="100"
+          :aria-label="`${t('usage.exportingProgress')}: ${normalizedProgress}%`"
+          class="h-2 rounded-full bg-primary-600 transition-all"
+          :style="{ width: `${normalizedProgress}%` }"
+        ></div>
+      </div>
+      <div v-if="estimatedTime" class="text-xs text-gray-500 dark:text-gray-400" aria-live="polite" aria-atomic="true">
+        {{ t('usage.estimatedTime', { time: estimatedTime }) }}
+      </div>
+    </div>
+
+    <template #footer>
+      <button
+        @click="handleCancel"
+        type="button"
+        class="rounded-md border border-gray-300 bg-white px-4 py-2 text-sm font-medium text-gray-700 hover:bg-gray-50 focus:outline-none focus:ring-2 focus:ring-primary-500 focus:ring-offset-2 dark:border-dark-600 dark:bg-dark-700 dark:text-gray-200 dark:hover:bg-dark-600 dark:focus:ring-offset-dark-800"
+      >
+        {{ t('usage.cancelExport') }}
+      </button>
+    </template>
+  </BaseDialog>
+</template>
+
+<script setup lang="ts">
+import { computed } from 'vue'
+import { useI18n } from 'vue-i18n'
+import BaseDialog from './BaseDialog.vue'
+
+interface Props {
+  show: boolean
+  progress: number
+  current: number
+  total: number
+  estimatedTime: string
+}
+
+interface Emits {
+  (e: 'cancel'): void
+}
+
+const props = defineProps<Props>()
+const emit = defineEmits<Emits>()
+const { t } = useI18n()
+
+const normalizedProgress = computed(() => {
+  const value = Number.isFinite(props.progress) ? props.progress : 0
+  return Math.min(100, Math.max(0, Math.round(value)))
+})
+
+const handleCancel = () => {
+  emit('cancel')
+}
+</script>