feat(workbench): refine dynamic task collaboration

src/features/workbench/hooks/use-workbench-agent.ts

@@ -89,6 +89,7 @@ export function useWorkbenchAgent({
   const [mobilePanelCollapsing, setMobilePanelCollapsing] = useState(false);
   const [sessionId, setSessionId] = useState<string | null>(null);
   const [sessionPurpose, setSessionPurpose] = useState<AgentSessionPurpose>("ordinary_chat");
+  const [sessionTaskId, setSessionTaskId] = useState<string | null>(null);
   const [registry, setRegistry] = useState<UIRegistry | null>(null);
   const [sessionTitle, setSessionTitle] = useState("新对话");
   const [statusLabel, setStatusLabel] = useState("Agent 后端连接中");
@@ -131,6 +132,7 @@ export function useWorkbenchAgent({
   const clearSessionId = useCallback(() => {
     sessionIdRef.current = null;
     setSessionId(null);
+    setSessionTaskId(null);
   }, []);
 
   const resolveRenderRef = useCallback((renderRef: string, nextSessionId: string) => {
@@ -549,6 +551,7 @@ export function useWorkbenchAgent({
 
         applySessionId(loadedSession.sessionId);
         setSessionPurpose(loadedSession.purpose);
+        setSessionTaskId(loadedSession.taskId ?? null);
         setSessionTitle(loadedSession.title);
         setStatusLabel("Agent 历史会话已打开");
         setPermissionOverrides({});
@@ -632,6 +635,7 @@ export function useWorkbenchAgent({
       clearSessionId();
       setSessionTitle("新对话");
       setSessionPurpose("ordinary_chat");
+      setSessionTaskId(null);
       setStatusLabel(nextStatusLabel);
       setConnectionStatus("online");
       setPermissionOverrides({});
@@ -917,6 +921,7 @@ export function useWorkbenchAgent({
     sessionHistoryLoading: sessionHistoryLoading || sessionHistoryValidating,
     sessionId,
     sessionPurpose,
+    sessionTaskId,
     sessionTitle,
     statusLabel,
     streamRenderState,