refactor(frontend): 清理ops组件中未使用的i18n翻译

- 移除i18n文件中未使用的翻译键（cpu, redis, qps, ttft等）
- 将技术术语改为硬编码（QPS, CPU, TPS等不需要翻译）
- 简化OpsDashboardHeader、OpsErrorDetailModal等组件的i18n调用

frontend/src/views/admin/ops/components/OpsThroughputTrendChart.vue

@@ -61,7 +61,7 @@ const chartData = computed(() => {
     labels: props.points.map((p) => formatHistoryLabel(p.bucket_start, props.timeRange)),
     datasets: [
       {
-        label: t('admin.ops.qps'),
+        label: 'QPS',
         data: props.points.map((p) => p.qps ?? 0),
         borderColor: colors.value.blue,
         backgroundColor: colors.value.blueAlpha,
@@ -183,7 +183,7 @@ function downloadChart() {
         <HelpTooltip v-if="!props.fullscreen" :content="t('admin.ops.tooltips.throughputTrend')" />
       </h3>
       <div class="flex items-center gap-2 text-xs text-gray-500 dark:text-gray-400">
-        <span class="flex items-center gap-1"><span class="h-2 w-2 rounded-full bg-blue-500"></span>{{ t('admin.ops.qps') }}</span>
+        <span class="flex items-center gap-1"><span class="h-2 w-2 rounded-full bg-blue-500"></span>QPS</span>
         <span class="flex items-center gap-1"><span class="h-2 w-2 rounded-full bg-green-500"></span>{{ t('admin.ops.tpsK') }}</span>
         <template v-if="!props.fullscreen">
           <button