fix(useChat): 修复 task_started 事件过滤及日志输出

- 增加 task_started 消息的调试日志，输出 task_id、topic_id、parent_task_id 和当前选中的话题
- 对 topic_id 不匹配的 task_started 消息进行过滤，并打印日志提示
- 对带有 parent_task_id 的孙智能体 TaskStarted 消息进行过滤，避免回填主视图，并打印日志
- 在更新消息状态时添加日志，记录查找 task tool_call 消息的数量及索引
- 处理未找到匹配 task tool_call 的情况并打印对应日志

web/src/hooks/useChat.ts

@@ -445,20 +445,30 @@ export function useChat(): UseChatReturn {
 
       case 'task_started': {
         const msg = message as TaskStarted
+        console.log('[useChat] task_started received:', { task_id: msg.task_id, topic_id: msg.topic_id, parent_task_id: msg.parent_task_id, selectedTopic: selectedTopicRef.current })
         // 只 backfill 当前话题的 task tool_call，避免跨话题串扰
-        if (msg.topic_id && msg.topic_id !== selectedTopicRef.current) break
+        if (msg.topic_id && msg.topic_id !== selectedTopicRef.current) {
+          console.log('[useChat] task_started filtered by topic_id')
+          break
+        }
         // 孙智能体的 TaskStarted 不应 backfill 到主视图
-        if (msg.parent_task_id) break
+        if (msg.parent_task_id) {
+          console.log('[useChat] task_started filtered by parent_task_id')
+          break
+        }
 
         // 设置 navigateToTaskId，让用户可以点击查看实时进度
         setMessages((prev) => {
+          console.log('[useChat] task_started searching messages for task tool_call, total messages:', prev.length)
           for (let i = prev.length - 1; i >= 0; i--) {
             if (prev[i].type === 'tool_call' && prev[i].toolName === 'task' && !prev[i].navigateToTaskId) {
+              console.log('[useChat] task_started SET navigateToTaskId at index', i, 'task_id:', msg.task_id)
               const updated = [...prev]
               updated[i] = { ...updated[i], navigateToTaskId: msg.task_id }
               return updated
             }
           }
+          console.log('[useChat] task_started NO matching task tool_call found in messages')
           return prev
         })
         break