feat(i18n): 全量中英文国际化改造

- 翻译 en-US.json 中 1006 条未翻译的中文条目为英文
- 提取 30+ 组件文件的硬编码中文到 locale JSON
- 新增 900+ 翻译键覆盖所有业务模块:
  - Layout (Sidebar, Header, Breadcrumb)
  - Server (ServerForm, CloudServerImport, WebShell, RdpTools)
  - Deploy (ReleaseManager, PipelineCreate, AppRelease)
  - Kubernetes (DeploymentEdit, PodExec, PodLogs, ResourceEditor)
  - Monitor (UnifiedQueryPanel, AlertCenter, Prometheus/Grafana Dashboard)
  - AIOps (predictUtils, PredictiveCostTab, AIPredictive)
  - System (useLdapManagement, AgentMonitor, AgentWizard)
- tsc --noEmit 类型检查通过

frontend/src/components/auth/Login.tsx

@@ -211,15 +211,15 @@ export function Login() {
 
         <div className="mt-6 pt-5 text-center text-xs space-y-1 border-t border-[var(--border-subtle)] dg-text-muted">
           <p>
-            默认管理员账号{' '}
+            {t('login.defaultAdminHint')}{' '}
             <span className="font-medium dg-text-secondary">admin / 123456</span>
           </p>
-          <p>LDAP 用户可直接使用域账号登录</p>
+          <p>{t('login.ldapHint')}</p>
         </div>
       </div>
 
       <p className="absolute bottom-4 left-0 right-0 text-center text-xs dg-text-muted opacity-60">
-        &copy; AIOps 智能运维平台
+        &copy; {t('login.copyright')}
       </p>
     </div>
   );