fix(frontend): complete i18n coverage and responsive layouts

frontend/src/views/user/WalletCenter.vue

@@ -682,6 +682,7 @@
 </template>
 
 <script setup lang="ts">
+import { getI18nLocale } from '@/i18n'
 import { computed, onBeforeUnmount, onMounted, reactive, ref, watch } from 'vue'
 import {
   Badge,
@@ -1327,7 +1328,7 @@ function handleRefundPageSizeChange(size: number) {
 
 function formatDateTime(value: string | null | undefined): string {
   if (!value) return '-'
-  return new Date(value).toLocaleString('zh-CN', {
+  return new Date(value).toLocaleString(getI18nLocale(), {
     year: 'numeric',
     month: '2-digit',
     day: '2-digit',