feat(i18n): 安全批量转换 135 文件 — 覆盖率 34%→62%

使用 i18n.t() 全局方式（避免 hook 定位问题）:
- 288 目标文件中 135 个成功转换
- 2228 处中文替换为 i18n.t() 调用
- 1006 个新翻译 key 添加到 zh-CN.json + en-US.json
- 词典总量: 3554 keys (22 namespaces)
- tsc 零错误 + Vite 构建成功
- 6 个含代码示例/数据字符串的文件安全回退

frontend/src/pages/monitor/middleware-monitor/MwOverviewCharts.tsx

@@ -10,6 +10,7 @@ import type { MwTarget } from './helpers';
 import { fmtHitRate, fmtVal } from './helpers';
 import { ChartExpandShell } from '../shared/ChartExpandShell';
 import { MonitorChartTooltip, MONITOR_PIE_STROKE, MonitorPieTooltip } from '../shared/monitorChartTheme';
+import i18n from '@/i18n';
 
 interface Props {
   targets: MwTarget[];
@@ -24,8 +25,8 @@ export function MwOverviewCharts({ targets }: Props) {
     const online = targets.filter((t) => t.status === 'online').length;
     const offline = targets.length - online;
     return [
-      { name: '在线', value: online, fill: 'var(--dg-green)' },
-      { name: '离线', value: offline, fill: 'var(--dg-red)' },
+      { name: i18n.t('agent.agentOnline'), value: online, fill: 'var(--dg-green)' },
+      { name: i18n.t('agent.agentOffline'), value: offline, fill: 'var(--dg-red)' },
     ].filter((d) => d.value > 0);
   }, [targets]);
 
@@ -52,7 +53,7 @@ export function MwOverviewCharts({ targets }: Props) {
 
   return (
     <div className="grid grid-cols-1 md:grid-cols-2 xl:grid-cols-4 gap-3">
-      <OverviewChartCard title="实例状态" icon={<PieChartIcon className="h-3.5 w-3.5 text-[var(--dg-text-muted)]" />} empty={statusData.length === 0}>
+      <OverviewChartCard title={i18n.t('monitor.mwoverviewchart.s2eeb27f9')} icon={<PieChartIcon className="h-3.5 w-3.5 text-[var(--dg-text-muted)]" />} empty={statusData.length === 0}>
         {(h) => (
           <ResponsiveContainer width="100%" height={h}>
             <PieChart>
@@ -66,13 +67,13 @@ export function MwOverviewCharts({ targets }: Props) {
         )}
       </OverviewChartCard>
 
-      <OverviewChartCard title="Redis 命中率" icon={<Percent className="h-3.5 w-3.5 text-[var(--dg-text-muted)]" />} empty={redisHitData.length === 0}>
+      <OverviewChartCard title={i18n.t('monitor.mwoverviewchart.s29d98d86')} icon={<Percent className="h-3.5 w-3.5 text-[var(--dg-text-muted)]" />} empty={redisHitData.length === 0}>
         {(h) => (
           <ResponsiveContainer width="100%" height={h}>
             <BarChart data={redisHitData} layout="vertical" margin={{ left: 0, right: 8 }}>
               <XAxis type="number" domain={[0, 100]} tick={{ fontSize: 9, fill: 'var(--dg-text-muted)' }} tickFormatter={(v) => `${v}%`} />
               <YAxis type="category" dataKey="name" width={64} tick={{ fontSize: 9, fill: 'var(--dg-text-muted)' }} tickLine={false} axisLine={false} />
-              <Tooltip content={<MonitorChartTooltip valueFormatter={(v) => fmtHitRate(v / 100)} nameFormatter={() => '命中率'} />} />
+              <Tooltip content={<MonitorChartTooltip valueFormatter={(v) => fmtHitRate(v / 100)} nameFormatter={() => i18n.t('monitor.mwtargetchartsp.s6787355b')} />} />
               <Bar dataKey="value" radius={[0, 3, 3, 0]} maxBarSize={14} isAnimationActive={false}>
                 {redisHitData.map((e) => <Cell key={e.fullName} fill={e.fill} />)}
               </Bar>
@@ -96,13 +97,13 @@ export function MwOverviewCharts({ targets }: Props) {
         )}
       </OverviewChartCard>
 
-      <OverviewChartCard title="MySQL 连接" icon={<BarChart3 className="h-3.5 w-3.5 text-[var(--dg-text-muted)]" />} empty={mysqlConnData.length === 0}>
+      <OverviewChartCard title={i18n.t('monitor.mwoverviewchart.s07d3e014')} icon={<BarChart3 className="h-3.5 w-3.5 text-[var(--dg-text-muted)]" />} empty={mysqlConnData.length === 0}>
         {(h) => (
           <ResponsiveContainer width="100%" height={h}>
             <BarChart data={mysqlConnData} layout="vertical" margin={{ left: 0, right: 8 }}>
               <XAxis type="number" tick={{ fontSize: 9, fill: 'var(--dg-text-muted)' }} />
               <YAxis type="category" dataKey="name" width={64} tick={{ fontSize: 9, fill: 'var(--dg-text-muted)' }} tickLine={false} axisLine={false} />
-              <Tooltip content={<MonitorChartTooltip valueFormatter={(v) => fmtVal(v)} nameFormatter={() => '连接'} />} />
+              <Tooltip content={<MonitorChartTooltip valueFormatter={(v) => fmtVal(v)} nameFormatter={() => i18n.t('monitor.mwoverviewchart.s30f7dd4e')} />} />
               <Bar dataKey="value" radius={[0, 3, 3, 0]} maxBarSize={14} isAnimationActive={false}>
                 {mysqlConnData.map((e) => <Cell key={e.fullName} fill={e.fill} />)}
               </Bar>