fix(i18n): U30 修复 8 处批量 i18n 转换损坏的调用 — DeploymentEditContainers/DeploymentEditStorage/AgentRuleDialog/LogFieldSidebar

损坏原因: 早期批量正则 i18n 转换 (U20 记录的 i18n.t() 损坏模式遗留) 将模板表达式/JSX
碎片错误包裹进 i18n.t() 调用, 产生运行时垃圾文本渲染.

修复清单:
- DeploymentEditContainers.tsx:85 — toast 调用 description 字段损坏 (i18n.t('), description: ...'))
- DeploymentEditStorage.tsx:175 — !manifest 空状态文案损坏
- DeploymentEditStorage.tsx:202 — 数据卷卡片副标题损坏
- AgentRuleDialog.tsx:111 — DialogDescription 损坏 (i18n.t('>阈值 {ruleForm.metric !== '))
- AgentRuleDialog.tsx:157 — 操作符 Label 损坏
- AgentRuleDialog.tsx:183 — 端口 Label 损坏
- AgentRuleDialog.tsx:195 — 持续时间 Label 损坏
- LogFieldSidebar.tsx:68 — 搜索框 placeholder 损坏

新增 i18n 键 (zh/en 对齐 7370→7376 +6):
- agent.ruleDialog.description / operator / port / duration
- kubernetes.storage.volumeDesc
- monitor.lbl.searchFields

验证: tsc -b=0, npm build✓ (17.99s), ESLint=0/53/0, go build=0, 17/17 测试通过

frontend/src/components/monitor/log-center/LogFieldSidebar.tsx

@@ -65,7 +65,7 @@ export function LogFieldSidebar({
         <input
           value={search}
           onChange={e => setSearch(e.target.value)}
-          placeholder={i18n.t('})${f.count ? ` · ${f.count} 个值` : ')}
+          placeholder={i18n.t('monitor.lbl.searchFields')}
           className="w-full h-7 pl-7 pr-2 text-xs rounded-md dg-input"
           style={{ background: 'var(--dg-bg-tertiary)', border: '1px solid var(--dg-border)', color: 'var(--dg-text-primary)' }}
         />