feat(chat): 支持子智能体导航添加子智能体类型参数

- 扩展 enterSubAgentView 方法，新增 subagentType 可选参数
- 更新相关回调 onNavigateToSubAgent，添加 subagentType 参数支持
- 调整 MessageBubble 组件触发子智能体导航时传递 subagentType
- 优化 MessageList 组件显示新消息计数及底部导航按钮交互
- 美化底部浮动导航按钮样式，增加新消息数字提示和动画
- TodoPanel 添加状态点样式，消息内容排版更紧凑
- 维护滚动位置状态，改进滚动时新消息计数逻辑

web/src/App.tsx

@@ -324,8 +324,8 @@ function App() {
   )
 
   const handleNavigateToSubAgent = useCallback(
-    (taskId: string, description: string) => {
-      const cmd = enterSubAgentView(taskId, description)
+    (taskId: string, description: string, subagentType?: string) => {
+      const cmd = enterSubAgentView(taskId, description, subagentType)
       handleCommand(cmd)
       sendMessage({ type: 'command', payload: JSON.stringify(cmd) })
     },

web/src/components/Chat/ChatContainer.tsx

@@ -8,7 +8,7 @@ interface ChatContainerProps {
   isReadOnly?: boolean
   channelName?: string
   onSendMessage: (content: string, attachments: Attachment[]) => void
-  onNavigateToSubAgent?: (taskId: string, description: string) => void
+  onNavigateToSubAgent?: (taskId: string, description: string, subagentType?: string) => void
   onStop?: () => void
   showThinking?: boolean
   /** 浮动待办面板，绝对定位在消息区域上方 */

web/src/components/Chat/MessageBubble.tsx

@@ -58,7 +58,7 @@ function StatusIcon({ status, size = 14 }: { status: 'calling' | 'result' | 'pen
 
 interface MessageBubbleProps {
   message: ChatMessage
-  onNavigateToSubAgent?: (taskId: string, description: string) => void
+  onNavigateToSubAgent?: (taskId: string, description: string, subagentType?: string) => void
   showThinking?: boolean
 }
 
@@ -477,7 +477,7 @@ export function MessageBubble({ message, onNavigateToSubAgent, showThinking = tr
                     <button
                       onClick={(e) => {
                         e.stopPropagation()
-                        onNavigateToSubAgent?.(taskResult.task_id, taskDescription || '子智能体任务')
+                        onNavigateToSubAgent?.(taskResult.task_id, taskDescription || '子智能体任务', subagentType)
                       }}
                       className="text-xs text-[var(--accent-cyan)] hover:text-[var(--accent-cyan)]/80 hover:underline transition-colors flex items-center gap-1"
                     >
@@ -491,7 +491,7 @@ export function MessageBubble({ message, onNavigateToSubAgent, showThinking = tr
                     <button
                       onClick={(e) => {
                         e.stopPropagation()
-                        onNavigateToSubAgent?.(message.subagentTaskId!, taskDescription || '子智能体任务')
+                        onNavigateToSubAgent?.(message.subagentTaskId!, taskDescription || '子智能体任务', subagentType)
                       }}
                       className="text-xs text-[var(--accent-cyan)] hover:text-[var(--accent-cyan)]/80 hover:underline transition-colors flex items-center gap-1"
                     >
@@ -551,7 +551,7 @@ export function MessageBubble({ message, onNavigateToSubAgent, showThinking = tr
                     <button
                       onClick={(e) => {
                         e.stopPropagation()
-                        onNavigateToSubAgent?.(taskResult.task_id, taskDescription || '子智能体任务')
+                        onNavigateToSubAgent?.(taskResult.task_id, taskDescription || '子智能体任务', subagentType)
                       }}
                       className="text-xs text-[var(--accent-cyan)] hover:text-[var(--accent-cyan)]/80 hover:underline transition-colors flex items-center gap-1"
                     >
@@ -581,7 +581,7 @@ export function MessageBubble({ message, onNavigateToSubAgent, showThinking = tr
                       <button
                         onClick={(e) => {
                           e.stopPropagation()
-                          onNavigateToSubAgent?.(message.subagentTaskId!, taskDescription || '子智能体任务')
+                          onNavigateToSubAgent?.(message.subagentTaskId!, taskDescription || '子智能体任务', subagentType)
                         }}
                         className="text-xs text-[var(--accent-cyan)] hover:text-[var(--accent-cyan)]/80 hover:underline transition-colors flex items-center gap-1"
                       >

web/src/components/Chat/MessageList.tsx

@@ -5,7 +5,7 @@ import { Sparkles, ArrowDown, ArrowUp } from 'lucide-react'
 
 interface MessageListProps {
   messages: ChatMessage[]
-  onNavigateToSubAgent?: (taskId: string, description: string) => void
+  onNavigateToSubAgent?: (taskId: string, description: string, subagentType?: string) => void
   showThinking?: boolean
   /** 视图标识，用于保存/恢复滚动位置。不同视图间切换时保持各自的滚动位置。 */
   viewKey?: string
@@ -16,7 +16,6 @@ export function MessageList({ messages, onNavigateToSubAgent, showThinking = tru
   const containerRef = useRef<HTMLDivElement>(null)
   const isAtBottomRef = useRef(true)
   const prevShowBottomRef = useRef(false)
-  const prevShowTopRef = useRef(false)
   const prevViewKeyRef = useRef(viewKey)
   const viewKeyRef = useRef(viewKey)
   viewKeyRef.current = viewKey
@@ -25,15 +24,14 @@ export function MessageList({ messages, onNavigateToSubAgent, showThinking = tru
   const scrollPositionsRef = useRef<Map<string, number>>(new Map())
 
   const [showScrollToBottom, setShowScrollToBottom] = useState(false)
-  const [showScrollToTop, setShowScrollToTop] = useState(false)
-  const [hasNewMessage, setHasNewMessage] = useState(false)
+  const [newMessageCount, setNewMessageCount] = useState(0)
 
   // ---- scroll helpers ----
 
   const scrollToBottom = useCallback((behavior: ScrollBehavior = 'smooth') => {
     isAtBottomRef.current = true
     setShowScrollToBottom(false)
-    setHasNewMessage(false)
+    setNewMessageCount(0)
     bottomRef.current?.scrollIntoView({ behavior })
   }, [])
 
@@ -58,22 +56,18 @@ export function MessageList({ messages, onNavigateToSubAgent, showThinking = tru
 
     isAtBottomRef.current = nearBottom
 
-    const shouldShowTop = el.scrollTop > el.clientHeight * 0.8
-    if (shouldShowTop !== prevShowTopRef.current) {
-      prevShowTopRef.current = shouldShowTop
-      setShowScrollToTop(shouldShowTop)
-    }
-
-    const shouldShowBottom = !nearBottom
+    // 回到底部：距底部 > 200px 时显示（同时显示回到顶部）
+    const shouldShowBottom = distanceFromBottom > 200
     if (shouldShowBottom !== prevShowBottomRef.current) {
       prevShowBottomRef.current = shouldShowBottom
       setShowScrollToBottom(shouldShowBottom)
     }
 
-    if (nearBottom && hasNewMessage) {
-      setHasNewMessage(false)
+    // 滚回底部时清除新消息计数
+    if (nearBottom) {
+      setNewMessageCount(0)
     }
-  }, [hasNewMessage])
+  }, [])
 
   // ---- auto-scroll: handle view switches and message updates ----
 
@@ -110,7 +104,7 @@ export function MessageList({ messages, onNavigateToSubAgent, showThinking = tru
     if (lastMessage.role === 'user' || isAtBottomRef.current) {
       bottomRef.current?.scrollIntoView({ behavior: 'instant' })
     } else {
-      setHasNewMessage(true)
+      setNewMessageCount((prev) => prev + 1)
     }
   }, [messages, viewKey])
 
@@ -158,14 +152,14 @@ export function MessageList({ messages, onNavigateToSubAgent, showThinking = tru
         <div ref={bottomRef} />
       </div>
 
-      {/* 浮动按钮 */}
-      <div className="absolute right-4 bottom-4 z-10 flex flex-col items-center gap-2 pointer-events-none">
-        {showScrollToTop && (
+      {/* 浮动导航按钮 — 底部居中并排 */}
+      {showScrollToBottom && (
+        <div className="absolute bottom-4 left-1/2 -translate-x-1/2 z-10 flex items-center gap-2">
+          {/* 回到顶部 */}
           <button
             onClick={scrollToTop}
-            className="pointer-events-auto group relative flex items-center justify-center
-                       w-9 h-9 rounded-full
-                       bg-[var(--bg-tertiary)]/80 backdrop-blur-md
+            className="flex items-center gap-1.5 px-3 py-2 rounded-full
+                       bg-[var(--bg-tertiary)]/90 backdrop-blur-md
                        border border-[var(--border-color)]
                        text-[var(--text-muted)] hover:text-[var(--accent-cyan)]
                        hover:border-[var(--accent-cyan)]/30
@@ -174,16 +168,15 @@ export function MessageList({ messages, onNavigateToSubAgent, showThinking = tru
                        animate-fade-in"
             aria-label="回到顶部"
           >
-            <ArrowUp className="h-4 w-4 transition-transform duration-300 group-hover:-translate-y-0.5" />
+            <ArrowUp className="h-4 w-4" />
+            <span className="text-sm text-[var(--text-secondary)]">顶部</span>
           </button>
-        )}
 
-        {showScrollToBottom && (
+          {/* 回到底部 */}
           <button
             onClick={() => scrollToBottom('smooth')}
-            className="pointer-events-auto group relative flex items-center justify-center
-                       w-9 h-9 rounded-full
-                       bg-[var(--bg-tertiary)]/80 backdrop-blur-md
+            className="flex items-center gap-2 px-4 py-2 rounded-full
+                       bg-[var(--bg-tertiary)]/90 backdrop-blur-md
                        border border-[var(--border-color)]
                        text-[var(--text-muted)] hover:text-[var(--accent-cyan)]
                        hover:border-[var(--accent-cyan)]/30
@@ -192,17 +185,23 @@ export function MessageList({ messages, onNavigateToSubAgent, showThinking = tru
                        animate-fade-in"
             aria-label="回到底部"
           >
-            <ArrowDown className={`h-4 w-4 transition-transform duration-300 group-hover:translate-y-0.5 ${hasNewMessage ? 'animate-bounce' : ''}`} />
-
-            {hasNewMessage && (
-              <span className="absolute -top-0.5 -right-0.5 flex h-2.5 w-2.5">
-                <span className="absolute inline-flex h-full w-full animate-ping rounded-full bg-[var(--accent-cyan)]/60"></span>
-                <span className="relative inline-flex h-2.5 w-2.5 rounded-full bg-[var(--accent-cyan)]"></span>
+            <ArrowDown className={`h-4 w-4 transition-transform duration-300 ${newMessageCount > 0 ? 'animate-bounce' : ''}`} />
+            {newMessageCount > 0 ? (
+              <span className="text-sm font-medium text-[var(--text-primary)]">
+                {newMessageCount} 条新消息
+              </span>
+            ) : (
+              <span className="text-sm text-[var(--text-secondary)]">回到最新</span>
+            )}
+            {newMessageCount > 0 && (
+              <span className="relative flex h-2 w-2">
+                <span className="absolute inline-flex h-full w-full animate-ping rounded-full bg-[var(--accent-cyan)]/60" />
+                <span className="relative inline-flex h-2 w-2 rounded-full bg-[var(--accent-cyan)]" />
               </span>
             )}
           </button>
-        )}
-      </div>
+        </div>
+      )}
     </div>
   )
 }

web/src/components/Panel/TodoPanel.tsx

@@ -236,7 +236,8 @@ export function TodoPanel({ todos, requestTodoList, sendCommand }: TodoPanelProp
                 {!isCollapsed && (
                   <div className="ml-3 border-l border-[var(--border-color)]/30 pl-2 mt-0.5 space-y-px">
                     {items.map(item => (
-                      <div key={item.id} className="py-[3px]">
+                      <div key={item.id} className="py-[3px] flex items-start gap-1.5">
+                        <span className={`h-1.5 w-1.5 rounded-full ${cfg.dot} shrink-0 mt-[5px]`} />
                         <span className="text-[12px] leading-snug text-[var(--text-primary)]/90 break-words">
                           {item.content}
                         </span>

web/src/hooks/useChat.ts

@@ -85,7 +85,7 @@ interface UseChatReturn {
   selectSession: (sessionId: string) => void
 
   // 子智能体导航方法
-  enterSubAgentView: (taskId: string, description: string) => Command
+  enterSubAgentView: (taskId: string, description: string, subagentType?: string) => Command
   exitSubAgentView: () => void
   navigateToSubAgentLevel: (index: number) => void
 
@@ -857,11 +857,11 @@ export function useChat(): UseChatReturn {
     selectedTopicRef.current = selectedTopic
   }, [selectedTopic])
 
-  const enterSubAgentView = useCallback((taskId: string, description: string): Command => {
+  const enterSubAgentView = useCallback((taskId: string, description: string, subagentType?: string): Command => {
     const newView: SubAgentView = {
       taskId,
       description,
-      subagentType: '',
+      subagentType: subagentType || '',
       status: 'loading',
       messages: [],
     }