fix(i18n): 回退到稳定的 32% 覆盖率状态 (tsc + Vite 构建通过)

批量转换脚本引入的语法错误已回退，保留稳定的 i18n 转换:
- 翻译词典: 22 namespaces, 3600+ keys
- 已接入: 145+ 文件 (Dashboard/Login/K8s 主页面/Monitor/System/Deploy)
- 语言切换器在 Header 中可用 (🇨🇳/🇺🇸)
- tsc 零错误, Vite 构建成功

frontend/src/components/system/SystemUserTab.tsx

@@ -28,6 +28,7 @@ import { UserDetailDialog } from './UserDetailDialog';
 import { CsvImportDialog } from './CsvImportDialog';
 import { LdapImportDialog } from './LdapImportDialog';
 import { usePermission } from '@/hooks/usePermission';
+import { useTranslation } from 'react-i18next';
 
 interface SystemUserTabProps {
   // Search
@@ -119,6 +120,7 @@ export function SystemUserTab({
   handleLdapImport,
   setLdapUsers,
 }: SystemUserTabProps) {
+  const { t } = useTranslation();
   const { hasPermission } = usePermission();
   const canManage = hasPermission('system:user');
 
@@ -140,7 +142,7 @@ export function SystemUserTab({
         <div className="relative w-64">
           <Search className="absolute left-3 top-1/2 -translate-y-1/2 h-4 w-4 text-[var(--dg-text-muted)]" />
           <Input
-            placeholder="搜索用户..."
+            placeholder={t('system.searchUserDot')}
             value={searchQuery}
             onChange={(e) => setSearchQuery(e.target.value)}
             className="pl-9 h-9 bg-[var(--dg-bg-tertiary)]/50 border-[var(--dg-border)] text-[var(--dg-text-primary)] placeholder:text-[var(--dg-text-muted)]"
@@ -150,13 +152,13 @@ export function SystemUserTab({
           {hasPermission('system:user') && (
           <Button variant="outline" className="border-[var(--dg-border)] text-[var(--dg-text-secondary)] hover:text-[var(--dg-text-primary)] hover:bg-[var(--dg-bg-hover)]" onClick={() => setImportDialogOpen('csv')}>
             <Upload className="h-4 w-4 mr-2" />
-            批量导入
+            {t('common.batchImport')}
           </Button>
           )}
           {hasPermission('system:user') && (
           <Button variant="outline" className="border-[var(--dg-border)] text-[var(--dg-text-secondary)] hover:text-[var(--dg-text-primary)] hover:bg-[var(--dg-bg-hover)]" onClick={() => setImportDialogOpen('ldap')}>
             <Network className="h-4 w-4 mr-2" />
-            LDAP 导入
+            {t('system.ldapImport')}
           </Button>
           )}
           {hasPermission('system:user') && (
@@ -175,11 +177,11 @@ export function SystemUserTab({
           </span>
           <div className="flex items-center gap-2">
             <Button variant="outline" size="sm" className="dg-btn-secondary" onClick={() => setSelectedUserIds([])}>
-              取消选择
+              {t('cloud.clearSelection')}
             </Button>
             <Button variant="outline" size="sm" className="dg-btn-danger dg-btn-sm" onClick={handleBatchDelete}>
               <Trash2 className="w-4 h-4 mr-2" />
-              批量删除
+              {t('system.terminalBatchDelete')}
             </Button>
           </div>
         </div>
@@ -201,13 +203,13 @@ export function SystemUserTab({
                       />
                     </TableHead>
                   )}
-                  <TableHead className="text-[var(--dg-text-secondary)]">用户信息</TableHead>
-                  <TableHead className="text-[var(--dg-text-secondary)]">联系方式</TableHead>
-                  <TableHead className="text-[var(--dg-text-secondary)]">角色</TableHead>
-                  <TableHead className="text-[var(--dg-text-secondary)]">来源</TableHead>
-                  <TableHead className="text-[var(--dg-text-secondary)]">状态</TableHead>
-                  <TableHead className="text-[var(--dg-text-secondary)]">最后登录</TableHead>
-                  <TableHead className="text-[var(--dg-text-secondary)] text-right">操作</TableHead>
+                  <TableHead className="text-[var(--dg-text-secondary)]">{t('system.userTitleField')}</TableHead>
+                  <TableHead className="text-[var(--dg-text-secondary)]">{t('system.contactInfo')}</TableHead>
+                  <TableHead className="text-[var(--dg-text-secondary)]">{t('system.userRole')}</TableHead>
+                  <TableHead className="text-[var(--dg-text-secondary)]">{t('common.source')}</TableHead>
+                  <TableHead className="text-[var(--dg-text-secondary)]">{t('system.userStatus')}</TableHead>
+                  <TableHead className="text-[var(--dg-text-secondary)]">{t('system.lastLogin')}</TableHead>
+                  <TableHead className="text-[var(--dg-text-secondary)] text-right">{t('system.auditAction')}</TableHead>
                 </TableRow>
               </TableHeader>
               <TableBody>