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/i18n/locales/en.ts

@@ -1858,10 +1858,8 @@ export default {
       noSystemMetrics: 'No system metrics collected yet.',
       collectedAt: 'Collected at:',
       window: 'window',
-      cpu: 'CPU',
       memory: 'Memory',
       db: 'DB',
-      redis: 'Redis',
       goroutines: 'Goroutines',
       jobs: 'Jobs',
       jobsHelp: 'Click “Details” to view job heartbeats and recent errors',
@@ -1907,7 +1905,6 @@ export default {
       p99: 'p99:',
       avg: 'avg:',
       max: 'max:',
-      qps: 'QPS',
       requests: 'Requests',
       requestsTitle: 'Requests',
       upstream: 'Upstream',
@@ -2061,7 +2058,6 @@ export default {
         },
         total: 'Total:',
         searchPlaceholder: 'Search request_id / client_request_id / message',
-        accountIdPlaceholder: 'account_id'
       },
       // Error Detail Modal
       errorDetail: {
@@ -2096,7 +2092,6 @@ export default {
           requestId: 'Request ID'
         },
         retryMeta: {
-          http: 'HTTP',
           used: 'Used',
           success: 'Success',
           pinned: 'Pinned'
@@ -2113,7 +2108,6 @@ export default {
         group: 'Group',
         account: 'Account',
         latency: 'Request Duration',
-        ttft: 'TTFT',
         businessLimited: 'Business Limited',
         requestPath: 'Request Path',
         timings: 'Timings',
@@ -2134,7 +2128,6 @@ export default {
         confirmRetry: 'Confirm Retry',
         retrySuccess: 'Retry succeeded',
         retryFailed: 'Retry failed',
-        na: 'N/A',
         retryHint: 'Retry will resend the request with the same parameters',
         retryClientHint: 'Use client retry (no account pinning)',
         retryUpstreamHint: 'Use upstream pinned retry (pin to the error account)',
@@ -2357,7 +2350,6 @@ export default {
           title: 'Alert Silencing (Maintenance Mode)',
           enabled: 'Enable silencing',
           globalUntil: 'Silence until (RFC3339)',
-          untilPlaceholder: '2026-01-05T00:00:00Z',
           untilHint: 'Leave empty to only toggle silencing without an expiry (not recommended).',
           reason: 'Reason',
           reasonPlaceholder: 'e.g., planned maintenance',

frontend/src/i18n/locales/zh.ts

@@ -2002,10 +2002,8 @@ export default {
       noSystemMetrics: '尚未收集系统指标。',
       collectedAt: '采集时间：',
       window: '窗口',
-      cpu: 'CPU',
       memory: '内存',
       db: '数据库',
-      redis: 'Redis',
       goroutines: '协程',
       jobs: '后台任务',
       jobsHelp: '点击“明细”查看任务心跳与报错信息',
@@ -2051,7 +2049,6 @@ export default {
       p99: 'p99',
       avg: 'avg',
       max: 'max',
-      qps: 'QPS',
       requests: '请求数',
       requestsTitle: '请求',
       upstream: '上游',
@@ -2205,7 +2202,6 @@ export default {
         },
         total: '总计：',
         searchPlaceholder: '搜索 request_id / client_request_id / message',
-        accountIdPlaceholder: 'account_id'
       },
       // Error Detail Modal
       errorDetail: {
@@ -2240,7 +2236,6 @@ export default {
           requestId: '请求ID'
         },
         retryMeta: {
-          http: 'HTTP',
           used: '使用账号',
           success: '成功',
           pinned: '固定账号'
@@ -2257,7 +2252,6 @@ export default {
         group: '分组',
         account: '账号',
         latency: '请求时长',
-        ttft: 'TTFT',
         businessLimited: '业务限制',
         requestPath: '请求路径',
         timings: '时序信息',
@@ -2278,7 +2272,6 @@ export default {
         confirmRetry: '确认重试',
         retrySuccess: '重试成功',
         retryFailed: '重试失败',
-        na: 'N/A',
         retryHint: '重试将使用相同的请求参数重新发送请求',
         retryClientHint: '使用客户端重试（不固定账号）',
         retryUpstreamHint: '使用上游固定重试（固定到错误的账号）',
@@ -2501,7 +2494,6 @@ export default {
           title: '告警静默（维护模式）',
           enabled: '启用静默',
           globalUntil: '静默截止时间（RFC3339）',
-          untilPlaceholder: '2026-01-05T00:00:00Z',
           untilHint: '建议填写截止时间，避免忘记关闭静默。',
           reason: '原因',
           reasonPlaceholder: '例如：计划维护',