media abstraction: add structured MediaItem model and expose media-source audit in task queue detail

webui/src/i18n/index.ts

@@ -18,6 +18,7 @@ const resources = {
       taskDetail: 'Task Detail',
       taskQueue: 'Task Queue',
       taskLogs: 'Task Logs',
+      mediaSources: 'Media Sources',
       error: 'Error',
       noTaskAudit: 'No task audit records',
       selectTask: 'Select a task from the left list',
@@ -170,6 +171,7 @@ const resources = {
       taskDetail: '任务详情',
       taskQueue: '任务队列',
       taskLogs: '任务日志',
+      mediaSources: '媒体来源',
       error: '错误',
       noTaskAudit: '暂无任务审计记录',
       selectTask: '请从左侧选择任务',