refactor(i18n): U29 phantom key 全项目清零 — 28 个 phantom key → 0

AlertRuleDialog.tsx (9处) + DeployTargetFields.tsx (3处) + HealthProbeSection.tsx (2处+1处硬编码) + PodLogsViewer.tsx (2处终端ANSI字符串) + AlertChannelDialog.tsx (2处) + PodMetricsPage.tsx/CapacityPage.tsx (各1处) + PodExecTerminal.tsx (1处终端ANSI) + BuildNodesManager.tsx (1处) + HostDetailDialog.tsx (1处)

修复类型:
- 批量正则损坏的 i18n.t('>中文 <span className=') → 语义化键
- 终端 ANSI 转义字符串 (PodLogsViewer/PodExecTerminal) → 移除 i18n.t() 包裹改纯字符串
- 硬编码中文 (取消/通知渠道提示/日志数据源提示) → i18n.t() 调用

新增 16 个翻译键 (monitor.alertRuleDialog2.* + monitor.alertChannel.name + agent.portCount + monitor.lbl.noProbeHint)
zh/en 7358→7375 +17 键对齐
phantom key 28→0 (全项目零 phantom key)
tsc -b=0, npm build✓ (17.00s), ESLint=0/53/0, go build=0, 17/17 测试通过

frontend/src/components/deploy/BuildNodesManager.tsx

@@ -293,7 +293,7 @@ export default function BuildNodesManager({ embedded = false }: { embedded?: boo
               <Input value={name} onChange={(e) => setName(e.target.value)} className="h-8 text-xs dg-input" placeholder="build-node-01" />
             </div>
             <div className="space-y-1">
-              <Label className="text-xs"> {i18n.t('>标签 <span className=')} </Label>
+              <Label className="text-xs"> {i18n.t('common.tag')} </Label>
               <Select value={serverId || '__none'} onValueChange={(v) => setServerId(v === '__none' ? '' : v)}>
                 <SelectTrigger className="h-8 text-xs dg-input"><SelectValue placeholder={i18n.t('deploy.buildNodes.selectServer')} /></SelectTrigger>
                 <SelectContent>