fix(logs): 域名筛选与残余原生 select 统一为可搜索/Radix Select

通病：/logs 域名筛选仍用 Input+datalist（与已修的快捷模板同类）；策略组数据源、数据源弹窗集群/鉴权仍为原生 select。改为 SearchableValueSelect / ui/select，并顺带理顺策略组列表空标签与用户勾选交互。采集器编辑里 app 预设 datalist 仍保留（自由输入场景）。

frontend/src/i18n/locales/en/logs.ts

@@ -146,6 +146,7 @@ export default {
     loadingQuery: 'Querying Loki',
     loadingWait: 'Waiting for {{seconds}}s. Wide-range queries may take a while.',
     pagingHint: 'Logs are paged newest to oldest; charts show the current page, and the top timeline covers the whole query range.',
+    domainAll: 'All domains',
     domainFilter: 'Domain filter',
     domainPlaceholder: 'Type or pick a domain',
     domainQuery: 'Query in Loki',
@@ -256,6 +257,7 @@ export default {
     loadFailed: 'Failed to load context',
   },
   access: {
+    labelsUnlimited: 'Unlimited · all namespaces',
     loadFailed: 'Failed to load query policies',
     validate: 'Fill in the policy group name, choose a data source, and select "Anyone" or at least one user',
     saveFailed: 'Failed to save policy group',