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/pages/monitor/host-monitor/HostTimeRangePicker.tsx

@@ -9,7 +9,6 @@ import {
   type TimeRangePresetId,
 } from './types';
 import { presetToRange, toDatetimeLocalValue, formatRangeSummary } from './timeRange';
-import { useTranslation } from 'react-i18next';
 
 interface Props {
   value: HostMonitorTimeRange;
@@ -17,7 +16,6 @@ interface Props {
 }
 
 export function HostTimeRangePicker({ value, onChange }: Props) {
-  const { t } = useTranslation();
   const [customOpen, setCustomOpen] = useState(false);
   const now = new Date();
   const [customStart, setCustomStart] = useState(toDatetimeLocalValue(new Date(now.getTime() - 3600_000)));
@@ -46,7 +44,7 @@ export function HostTimeRangePicker({ value, onChange }: Props) {
     const e = start.getTime() <= end.getTime() ? end : start;
     onChange({
       preset: 'custom',
-      label: t('common.custom'),
+      label: '自定义',
       start: s.toISOString(),
       end: e.toISOString(),
       buckets: Math.min(120, Math.max(36, Math.ceil((e.getTime() - s.getTime()) / 60_000 / 2))),
@@ -87,10 +85,10 @@ export function HostTimeRangePicker({ value, onChange }: Props) {
           </Button>
           {customOpen && (
             <div className="absolute right-0 top-full mt-1 z-50 w-72 rounded-lg border border-[var(--dg-border)] bg-[var(--dg-bg-primary)] p-3 shadow-lg">
-              <p className="text-xs font-medium text-[var(--dg-text-primary)] mb-2">{t('monitor.hosttimerangepicker.s0122e0')}</p>
+              <p className="text-xs font-medium text-[var(--dg-text-primary)] mb-2">自定义时间范围</p>
               <div className="space-y-2">
                 <div>
-                  <label className="text-[10px] dg-text-muted">{t('common.start')}</label>
+                  <label className="text-[10px] dg-text-muted">开始</label>
                   <Input
                     type="datetime-local"
                     value={customStart}
@@ -99,7 +97,7 @@ export function HostTimeRangePicker({ value, onChange }: Props) {
                   />
                 </div>
                 <div>
-                  <label className="text-[10px] dg-text-muted">{t('monitor.hosttimerangepicker.s12f1d7')}</label>
+                  <label className="text-[10px] dg-text-muted">结束</label>
                   <Input
                     type="datetime-local"
                     value={customEnd}