fix: 协助卡停轮与提交防 409，隐藏配置向导会话，并限制岗位会商产物重复写入

澄清中间件改为 ToolMessage + after_model 停轮，前端提交前取消残留 run；系统/向导 thread_type 从对话列表排除；岗位总结席位加 write_file 上限。

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend-web/src/components/workspace/agents/agent-chat-sidebar.tsx

@@ -72,6 +72,7 @@ import type { AgentThread, AgentThreadState } from "@/core/threads/types";
 import {
   bootstrapResumePath,
   isBootstrapThread,
+  isHiddenFromRecentChats,
   isThreadFavorite,
   isThreadPinned,
   sortThreadsPinnedFirst,
@@ -372,17 +373,10 @@ function RecentChatsPane({ activeAgentId }: { activeAgentId?: string }) {
   const [renameValue, setRenameValue] = useState("");
   const [shareThreadId, setShareThreadId] = useState<string | null>(null);
 
-  // 排除调度/会商类系统会话，与首页一致；智能体创建（bootstrap）会话保留展示
-  // （带机器人图标、点击回创建页）；置顶优先。
+  // 排除调度/会商/报告结构&写作配置向导等系统会话，与首页一致；
+  // 智能体创建（bootstrap）会话保留展示（带机器人图标、点击回创建页）；置顶优先。
   const visibleThreads = useMemo(
-    () =>
-      sortThreadsPinnedFirst(
-        threads.filter(
-          (thread) =>
-            thread.metadata?.thread_type !== "scheduler" &&
-            thread.metadata?.thread_type !== "roundtable",
-        ),
-      ),
+    () => sortThreadsPinnedFirst(threads.filter((thread) => !isHiddenFromRecentChats(thread))),
     [threads],
   );
 

frontend-web/src/components/workspace/agents/agent-recent-chats.tsx

@@ -5,7 +5,7 @@ import Link from "next/link";
 import { usePathname } from "next/navigation";
 
 import { useThreadsPage } from "@/core/threads/hooks";
-import { pathOfThread, titleOfThread } from "@/core/threads/utils";
+import { pathOfThread, titleOfThread, isHiddenFromRecentChats, isBootstrapThread } from "@/core/threads/utils";
 import { desensitize } from "@/lib/desensitize";
 import { cn } from "@/lib/utils";
 
@@ -22,12 +22,9 @@ export function AgentRecentChats({ agentId }: { agentId: string }) {
     pageSize: RECENT_LIMIT,
     metadata: { agent_id: agentId },
   });
-  // 该智能体的会话里同样排除调度 / 引导 / 会商类系统会话。
+  // 该智能体的会话里同样排除引导 / 系统 / 配置向导会话。
   const threads = (data?.threads ?? []).filter(
-    (th) =>
-      th.metadata?.thread_type !== "bootstrap" &&
-      th.metadata?.thread_type !== "scheduler" &&
-      th.metadata?.thread_type !== "roundtable",
+    (th) => !isBootstrapThread(th) && !isHiddenFromRecentChats(th),
   );
 
   return (

frontend-web/src/components/workspace/general-qa-sidebar.tsx

@@ -76,6 +76,7 @@ import {
 import type { AgentThread, AgentThreadState } from "@/core/threads/types";
 import {
   isBootstrapThread,
+  isHiddenFromRecentChats,
   isThreadFavorite,
   isThreadPinned,
   listPathOfThread,
@@ -226,14 +227,8 @@ export function GeneralQaSidebar() {
   const visibleThreads = useMemo(
     () =>
       // 智能体创建（bootstrap）会话也展示（带机器人图标、点击回创建页）；
-      // 仅排除调度 / 会商类系统会话。
-      sortThreadsPinnedFirst(
-        threads.filter(
-          (thread) =>
-            thread.metadata?.thread_type !== "scheduler" &&
-            thread.metadata?.thread_type !== "roundtable",
-        ),
-      ),
+      // 排除调度 / 会商 / 报告结构&写作配置向导等系统会话。
+      sortThreadsPinnedFirst(threads.filter((thread) => !isHiddenFromRecentChats(thread))),
     [threads],
   );
 

frontend-web/src/components/workspace/recent-chat-list.tsx

@@ -66,6 +66,7 @@ import {
 import type { AgentThread, AgentThreadState } from "@/core/threads/types";
 import {
   isBootstrapThread,
+  isHiddenFromRecentChats,
   isThreadFavorite,
   isThreadPinned,
   listPathOfThread,
@@ -193,13 +194,9 @@ export function RecentChatList({
   );
 
   // 智能体创建（bootstrap）会话也展示在常用对话里（带机器人图标、点击回创建页）；
-  // 仅排除调度 / 会商类系统会话。
+  // 排除调度 / 会商 / 报告结构&写作配置向导等系统会话。
   const visibleThreads = sortThreadsPinnedFirst(
-    threads.filter(
-      (thread) =>
-        thread.metadata?.thread_type !== "scheduler" &&
-        thread.metadata?.thread_type !== "roundtable",
-    ),
+    threads.filter((thread) => !isHiddenFromRecentChats(thread)),
   );
 
   if (visibleThreads.length === 0) {

frontend-web/src/core/studio/hooks.ts

@@ -99,8 +99,14 @@ export function useNotebookChat(
     },
   });
 
-  const send = async (text: string, selectedSourceIds: number[]) => {
-    if (thread.isLoading || !token) return;
+  const send = async (
+    text: string,
+    selectedSourceIds: number[],
+    options?: { fromClarification?: boolean },
+  ) => {
+    if (!token) return;
+    // 协助卡提交前会先停轮；此时 isLoading 可能仍为 true，不能直接丢弃。
+    if (thread.isLoading && !options?.fromClarification) return;
     // API 需要 document.id，而不是 source.id
     const toDocIds = (ids: number[]) =>
       ids

frontend-web/src/core/threads/hooks.ts

@@ -28,6 +28,7 @@ import {
   isAbortLikeError,
   isTransientStreamTransportError,
 } from "./thread-access-error";
+import { isHiddenFromRecentChats, shouldHideSystemThreadsFromList } from "./utils";
 
 export type ToolEndEvent = {
   name: string;
@@ -210,6 +211,39 @@ export async function stopThreadRun(
   }
 }
 
+/**
+ * 协助卡提交前：若上一轮还在流式（弱模型出卡后偶发未停干净），先取消服务端 run
+ * 并断开本地 SSE，避免 409「已有活跃 run」或用户点了选项却发不出去。
+ */
+export async function stopActiveThreadBeforeClarificationReply(
+  threadId: string | null | undefined,
+  thread: { isLoading?: boolean; stop: () => void | Promise<void> },
+): Promise<void> {
+  let storedRunId: string | null = null;
+  if (threadId && typeof window !== "undefined") {
+    try {
+      storedRunId = normalizeStoredRunId(
+        window.sessionStorage.getItem(`lg:stream:${threadId}`),
+      );
+    } catch {
+      storedRunId = null;
+    }
+  }
+  if (!thread.isLoading && !storedRunId) return;
+  try {
+    await stopThreadRun(threadId);
+  } catch {
+    /* best-effort */
+  }
+  try {
+    await Promise.resolve(thread.stop());
+  } catch {
+    /* best-effort */
+  }
+  // cancel 落地需要一拍，立刻 submit 仍可能 409。
+  await new Promise((resolve) => setTimeout(resolve, 120));
+}
+
 function getStreamErrorMessage(error: unknown): string {
   if (typeof error === "string" && error.trim()) {
     return error;
@@ -1451,18 +1485,10 @@ export function useThreads(
       }
 
       // Safety net on top of the backend's system-thread exclusion: drop
-      // machine-created threads (scheduled tasks, roundtable workers,
-      // notebooks) in case an older backend still returns them.
-      return threads.filter((t) => {
-        const metadata = t.metadata as Record<string, unknown> | null;
-        if (metadata?.system) return false;
-        const threadType = metadata?.thread_type;
-        return (
-          threadType !== "notebook" &&
-          threadType !== "scheduler" &&
-          threadType !== "roundtable"
-        );
-      });
+      // machine-created / wizard threads (scheduled tasks, report-structure
+      // setup, writing setup, notebooks, …) in case an older backend still
+      // returns them.
+      return threads.filter((t) => !isHiddenFromRecentChats(t));
     },
     refetchOnWindowFocus: false,
   });
@@ -1545,8 +1571,13 @@ export function useThreadsPage(options: {
         throw new Error("Failed to load conversations");
       }
       const rows = (await response.json()) as AgentThread[];
+      // 与后端 exclude_system 对齐：普通列表再兜一层。调用方显式按
+      // thread_type / system 取数（笔记本等）时不滤，避免把目标会话藏掉。
+      const visible = shouldHideSystemThreadsFromList(metadata)
+        ? rows.filter((thread) => !isHiddenFromRecentChats(thread))
+        : rows;
       return {
-        threads: rows.slice(0, pageSize),
+        threads: visible.slice(0, pageSize),
         hasMore: rows.length > pageSize,
       };
     },

frontend-web/src/core/threads/utils.ts

@@ -91,6 +91,44 @@ export function isBootstrapThread(thread: {
   return thread.metadata?.thread_type === "bootstrap";
 }
 
+/**
+ * 不应出现在普通对话列表里的 thread_type。
+ * 与后端 ``EXCLUDED_SYSTEM_THREAD_TYPES`` 保持同步；bootstrap 不在此列（侧栏仍展示）。
+ */
+export const HIDDEN_FROM_RECENT_CHAT_TYPES = new Set([
+  "scheduler",
+  "roundtable",
+  "notebook",
+  "deep_research",
+  "writing_setup",
+  "report_structure_setup",
+]);
+
+export function isSetupWizardThread(thread: {
+  metadata?: Record<string, unknown> | null;
+}): boolean {
+  const threadType = thread.metadata?.thread_type;
+  return threadType === "writing_setup" || threadType === "report_structure_setup";
+}
+
+/** 侧栏 / 全部对话应隐藏的系统 / 向导会话（bootstrap 除外，仍会展示）。 */
+export function isHiddenFromRecentChats(thread: {
+  metadata?: Record<string, unknown> | null;
+}): boolean {
+  const metadata = thread.metadata;
+  if (metadata?.system === true) return true;
+  const threadType = metadata?.thread_type;
+  return typeof threadType === "string" && HIDDEN_FROM_RECENT_CHAT_TYPES.has(threadType);
+}
+
+/** 调用方显式按 thread_type / system 过滤时，不要再套一层「最近对话」隐藏。 */
+export function shouldHideSystemThreadsFromList(
+  metadata?: Record<string, unknown> | null,
+): boolean {
+  if (!metadata) return true;
+  return !("thread_type" in metadata || "system" in metadata);
+}
+
 /**
  * bootstrap 会话点击后回到「创建智能体」页并恢复该会话。该页只挂在
  * /page/workspace 下（见 WorkspaceRoutes 的 agents/new/:thread_id），故路径固定，

frontend-web/src/open-canvas/components/ai-writing/WritingSetupChat.tsx

@@ -26,7 +26,7 @@ import { ThreadContext } from '@/components/workspace/messages/context';
 import { extractContentFromMessage, extractReasoningContentFromMessage, hasToolCalls } from '@/core/messages/utils';
 import { getAPIClient } from '@/core/api';
 import { useModels } from '@/core/models/hooks';
-import { useThreadStream } from '@/core/threads/hooks';
+import { stopActiveThreadBeforeClarificationReply, useThreadStream } from '@/core/threads/hooks';
 import { uuid } from '@/core/utils/uuid';
 import { cn } from '@/lib/utils';
 
@@ -146,7 +146,10 @@ export function WritingSetupChat({
 
   const ensureThreadExists = useCallback(async () => {
     if (threadPrepared) return;
-    await getAPIClient().threads.create({ threadId, metadata: { thread_type: 'writing_setup' } });
+    await getAPIClient().threads.create({
+      threadId,
+      metadata: { thread_type: 'writing_setup', system: true },
+    });
     setThreadPrepared(true);
   }, [threadId, threadPrepared]);
 
@@ -167,15 +170,9 @@ export function WritingSetupChat({
 
   const handleClarificationSubmit = useCallback(
     async (text: string) => {
-      if (thread.isLoading) {
-        try {
-          await Promise.resolve(thread.stop());
-        } catch {
-          /* still send the answer */
-        }
-      }
       const trimmed = text.trim();
       if (!trimmed) return;
+      await stopActiveThreadBeforeClarificationReply(threadId, thread);
       await ensureThreadExists();
       await sendMessage(threadId, { text: trimmed, files: [] }, buildWritingSampleContext(formCtx));
     },

frontend-web/src/open-canvas/components/chat/CanvasChatPanel.tsx

@@ -36,6 +36,7 @@ import { Textarea } from "@/components/ui/textarea";
 import { MessageList } from "@/components/workspace/messages";
 import { useModels } from "@/core/models/hooks";
 import type { AgentThreadState } from "@/core/threads";
+import { stopActiveThreadBeforeClarificationReply } from "@/core/threads/hooks";
 import { cn } from "@/lib/utils";
 
 import { useCanvasGraphContext } from "../../contexts/CanvasGraphContext";
@@ -177,9 +178,10 @@ export function CanvasChatPanel() {
 
   const handleClarificationSubmit = useCallback(
     async (answer: string) => {
+      await stopActiveThreadBeforeClarificationReply(threadId, thread);
       await sendMessage(answer, { mode });
     },
-    [sendMessage, mode],
+    [sendMessage, mode, thread, threadId],
   );
 
   const handleModelSelect = useCallback(

frontend-web/src/pages/AgentChatPage.tsx

@@ -31,7 +31,7 @@ import { queueLlmWikiConversationDeposit } from "@/core/llmwiki/conversation-dep
 import { useModels } from "@/core/models/hooks";
 import { useNotification } from "@/core/notification/hooks";
 import { saveLastAgentId, useThreadSettings } from "@/core/settings";
-import { stopThreadRun, useThreadStream } from "@/core/threads/hooks";
+import { stopActiveThreadBeforeClarificationReply, stopThreadRun, useThreadStream } from "@/core/threads/hooks";
 import { textOfMessage } from "@/core/threads/utils";
 import { OptType, writeYLog } from "@/core/log/y-log";
 import {
@@ -542,11 +542,12 @@ export default function AgentChatPage({
   }, [taskAutoStart, taskStartText, isNewThread, handleSubmit]);
 
   const handleClarificationSubmit = useCallback(
-    (answer: string) => {
+    async (answer: string) => {
       setHasStartedConversation(true);
-      void sendMessage(threadId, { text: answer, files: [] }, { agent_id });
+      await stopActiveThreadBeforeClarificationReply(threadId, thread);
+      await sendMessage(threadId, { text: answer, files: [] }, { agent_id });
     },
-    [sendMessage, threadId, agent_id],
+    [sendMessage, thread, threadId, agent_id],
   );
 
   const handleStop = useCallback(async () => {

frontend-web/src/pages/ChatPage.tsx

@@ -58,7 +58,7 @@ import {
   useKnowledgeRagEnabled,
   useThreadSettings,
 } from "@/core/settings";
-import { useThreadStream } from "@/core/threads/hooks";
+import { useThreadStream, stopActiveThreadBeforeClarificationReply } from "@/core/threads/hooks";
 import { queueLlmWikiConversationDeposit } from "@/core/llmwiki/conversation-deposit";
 import { useSingleRoundRagMessages } from "@/core/threads/use-single-round-rag";
 import { useMultiRoundRagMessages } from "@/core/threads/use-multi-round-rag";
@@ -525,11 +525,12 @@ export default function ChatPage() {
   );
 
   const handleClarificationSubmit = useCallback(
-    (answer: string) => {
+    async (answer: string) => {
       setHasStartedConversation(true);
-      void sendMessage(threadId, { text: answer, files: [] });
+      await stopActiveThreadBeforeClarificationReply(threadId, thread);
+      await sendMessage(threadId, { text: answer, files: [] });
     },
-    [sendMessage, threadId],
+    [sendMessage, thread, threadId],
   );
 
   useEffect(() => {

frontend-web/src/pages/EmbedChatPage.tsx

@@ -9,7 +9,7 @@ import { setStoredAuth } from "@/core/auth";
 import { resolveEmbedChatParams } from "@/core/embed/params";
 import { registerEmbedSession } from "@/core/embed/status-api";
 import { useThreadSettings } from "@/core/settings";
-import { useThreadStream } from "@/core/threads/hooks";
+import { stopActiveThreadBeforeClarificationReply, useThreadStream } from "@/core/threads/hooks";
 import { uuid } from "@/core/utils/uuid";
 import { ChatBox } from "@/components/workspace/chats";
 import {
@@ -110,10 +110,11 @@ export default function EmbedChatPage() {
   }, [authReady, threadId, registerSessionForThread]);
 
   const handleClarificationSubmit = useCallback(
-    (answer: string) => {
-      void sendMessage(threadId, { text: answer, files: [] });
+    async (answer: string) => {
+      await stopActiveThreadBeforeClarificationReply(threadId, thread);
+      await sendMessage(threadId, { text: answer, files: [] });
     },
-    [sendMessage, threadId],
+    [sendMessage, thread, threadId],
   );
 
   useEffect(() => {

frontend-web/src/pages/IframeChatPage.tsx

@@ -40,7 +40,7 @@ import {
   useThreadSettings,
 } from "@/core/settings";
 import { usePluginManagementSettings } from "@/core/system-settings/hooks";
-import { useThreadStream } from "@/core/threads/hooks";
+import { stopActiveThreadBeforeClarificationReply, useThreadStream } from "@/core/threads/hooks";
 import { textOfMessage } from "@/core/threads/utils";
 import { env } from "@/env";
 import { cn } from "@/lib/utils";
@@ -336,11 +336,12 @@ export default function IframeChatPage() {
   );
 
   const handleClarificationSubmit = useCallback(
-    (answer: string) => {
+    async (answer: string) => {
       setHasStartedConversation(true);
-      void sendMessage(threadId, { text: answer, files: [] });
+      await stopActiveThreadBeforeClarificationReply(threadId, thread);
+      await sendMessage(threadId, { text: answer, files: [] });
     },
-    [sendMessage, threadId],
+    [sendMessage, thread, threadId],
   );
 
   const handleAgentChange = useCallback((agentId: string | null) => {

frontend-web/src/pages/NewAgentPage.tsx

@@ -53,7 +53,7 @@ import { useI18n } from "@/core/i18n/hooks";
 import { useModels } from "@/core/models/hooks";
 import { isAgentSkillCandidate } from "@/core/skills";
 import { useSkills } from "@/core/skills/hooks";
-import { useThreadStream } from "@/core/threads/hooks";
+import { stopActiveThreadBeforeClarificationReply, useThreadStream } from "@/core/threads/hooks";
 import { uuid } from "@/core/utils/uuid";
 import { cn } from "@/lib/utils";
 
@@ -335,13 +335,25 @@ export default function NewAgentPage() {
       // Chat is purely a discussion channel. The agent record is only
       // created when the user explicitly clicks Save (top-right). If the
       // model proposes a config via setup_agent, our approval handler
-      // prefills the form locally 鈥?it does NOT persist anything.
+      // prefills the form locally — it does NOT persist anything.
       await ensureThreadExists();
       await sendMessage(threadId, { text: trimmed, files: [] });
     },
     [ensureThreadExists, sendMessage, thread.isLoading, threadId],
   );
 
+  const handleClarificationSubmit = useCallback(
+    async (text: string) => {
+      const trimmed = text.trim();
+      if (!trimmed) return;
+      // 协助卡提交不能因 isLoading 直接丢弃——弱模型出卡后可能仍在流式。
+      await stopActiveThreadBeforeClarificationReply(threadId, thread);
+      await ensureThreadExists();
+      await sendMessage(threadId, { text: trimmed, files: [] });
+    },
+    [ensureThreadExists, sendMessage, thread, threadId],
+  );
+
   const handleApproveSetupAgent = useCallback(
     async (payload: SetupAgentApprovalPayload) => {
       // Approving the model's setup_agent proposal **does not** persist
@@ -425,7 +437,7 @@ export default function NewAgentPage() {
                   className="size-full"
                   threadId={threadId}
                   thread={thread}
-                  onClarificationSubmit={handleChatSubmit}
+                  onClarificationSubmit={handleClarificationSubmit}
                   onSetupAgentApprove={handleApproveSetupAgent}
                   onSetupAgentReject={handleRejectSetupAgent}
                 />

frontend-web/src/pages/StudioNotebookDetailPage.tsx

@@ -25,6 +25,7 @@ import {
   DialogTitle,
 } from "@/components/ui/dialog";
 import { useNotebookChat, useNotebookSources, useNotebookThreads, useStudioNotebooks } from "@/core/studio/hooks";
+import { stopActiveThreadBeforeClarificationReply } from "@/core/threads/hooks";
 import { fetchDocumentByChunk } from "@/core/studio/api";
 import type { DocumentWithChunks } from "@/core/studio/api";
 import type { SourceItem } from "@/core/studio/types";
@@ -381,12 +382,13 @@ export default function StudioNotebookDetailPage({
   // Clarification 卡片的「发送」按钮回调。MessageList 内部把用户选中的选项 +
   // 自由文本合并成一段 answer 传过来，这里走和普通发送同一条 send() 链路，
   // 把当前选中的来源也一并带上，保持上下文一致。
+  // 弱模型出卡后可能仍在流式：先 stop 再发，不能因 isStreaming 直接丢弃。
   const handleClarificationSubmit = useCallback(
     async (answer: string) => {
-      if (isStreaming) return;
-      await send(answer, selectedSourceIds);
+      await stopActiveThreadBeforeClarificationReply(chatThreadId, thread);
+      await send(answer, selectedSourceIds, { fromClarification: true });
     },
-    [send, selectedSourceIds, isStreaming],
+    [send, selectedSourceIds, chatThreadId, thread],
   );
 
   const handleBackToList = () => {

frontend-web/src/pages/deep-research/DeepResearchWorkbench.tsx

@@ -87,7 +87,11 @@ import { useLocalSettings } from "@/core/settings/hooks";
 import { useModels } from "@/core/models/hooks";
 import type { DocumentRewriteStreamEvent, DocumentRewriteSummary } from "@/open-canvas/api/rewrite";
 import { useDocumentRewrite } from "@/open-canvas/hooks/useDocumentRewrite";
-import { stopThreadRun, useThreadStream } from "@/core/threads/hooks";
+import {
+  stopActiveThreadBeforeClarificationReply,
+  stopThreadRun,
+  useThreadStream,
+} from "@/core/threads/hooks";
 import {
   extractContentFromMessage,
   extractReasoningContentFromMessage,
@@ -947,9 +951,11 @@ function DeepResearchWorkbenchInner() {
 
   const handleClarificationSubmit = useCallback(
     async (text: string) => {
+      const threadId = session?.runtimeThreadId;
+      await stopActiveThreadBeforeClarificationReply(threadId, collectorThread);
       await sendCollectorMessage(text);
     },
-    [sendCollectorMessage],
+    [collectorThread, sendCollectorMessage, session?.runtimeThreadId],
   );
 
   // The very first research topic: auto-sent into the freshly pre-built

frontend-web/src/pages/deep-research/ReportStructureSetupChat.tsx

@@ -28,7 +28,7 @@ import { extractContentFromMessage, extractReasoningContentFromMessage, hasToolC
 import { getAPIClient } from "@/core/api";
 import { useModels } from "@/core/models/hooks";
 import { useSkills } from "@/core/skills/hooks";
-import { useThreadStream } from "@/core/threads/hooks";
+import { stopActiveThreadBeforeClarificationReply, useThreadStream } from "@/core/threads/hooks";
 import { uuid } from "@/core/utils/uuid";
 import { cn } from "@/lib/utils";
 
@@ -79,7 +79,10 @@ export function ReportStructureSetupChat({
 
   const ensureThreadExists = useCallback(async () => {
     if (threadPrepared) return;
-    await getAPIClient().threads.create({ threadId, metadata: { thread_type: "report_structure_setup" } });
+    await getAPIClient().threads.create({
+      threadId,
+      metadata: { thread_type: "report_structure_setup", system: true },
+    });
     setThreadPrepared(true);
   }, [threadId, threadPrepared]);
 
@@ -99,15 +102,9 @@ export function ReportStructureSetupChat({
 
   const handleClarificationSubmit = useCallback(
     async (text: string) => {
-      if (thread.isLoading) {
-        try {
-          await Promise.resolve(thread.stop());
-        } catch {
-          /* best-effort: still send the answer */
-        }
-      }
       const trimmed = text.trim();
       if (!trimmed) return;
+      await stopActiveThreadBeforeClarificationReply(threadId, thread);
       await ensureThreadExists();
       await sendMessage(threadId, { text: trimmed, files: [] });
     },

frontend-web/src/position-roundtable/components/PositionBuiltinAgentChat.tsx

@@ -9,7 +9,7 @@ import { MessageList } from "@/components/workspace/messages";
 import { ThreadContext } from "@/components/workspace/messages/context";
 import { useAgent } from "@/core/agents";
 import { useLocalSettings } from "@/core/settings";
-import { useThreadStream } from "@/core/threads/hooks";
+import { stopActiveThreadBeforeClarificationReply, useThreadStream } from "@/core/threads/hooks";
 import type { AgentThreadState } from "@/core/threads/types";
 import { textOfMessage } from "@/core/threads/utils";
 import { uuid } from "@/core/utils/uuid";
@@ -460,7 +460,10 @@ export function PositionBuiltinAgentChat({
   );
 
   const handleSubmit = useCallback(
-    async (message: PromptInputMessage) => {
+    async (
+      message: PromptInputMessage,
+      options?: { fromClarification?: boolean },
+    ) => {
       if (!session) {
         toast.warning("请先启动业务链");
         return;
@@ -469,7 +472,9 @@ export function PositionBuiltinAgentChat({
         toast.info(readOnlyHint || "当前阶段暂不可对话");
         return;
       }
-      if (pendingSubmissionRef.current || thread.isLoading) {
+      if (options?.fromClarification) {
+        pendingSubmissionRef.current = false;
+      } else if (pendingSubmissionRef.current || thread.isLoading) {
         return;
       }
       pendingSubmissionRef.current = true;
@@ -540,6 +545,8 @@ export function PositionBuiltinAgentChat({
           {
             agent_id: submission.agentId,
             ...(selectedModel ? { model: selectedModel } : {}),
+            // Summary: one Markdown only. Action-plan needs report + JSON — no cap.
+            ...(kind === "summary" ? { position_artifact_cap: 1 } : {}),
           },
           {
             hiddenContext: {
@@ -683,9 +690,18 @@ export function PositionBuiltinAgentChat({
             // Use the built-in agent's regular submit path. This keeps a
             // clarification answer on the same persisted thread and retains
             // the summary/action-plan preparation and completion lifecycle.
-            onClarificationSubmit={(answer) =>
-              handleSubmit({ text: answer, files: [] })
-            }
+            onClarificationSubmit={(answer) => {
+              void (async () => {
+                await stopActiveThreadBeforeClarificationReply(
+                  boundThreadId ?? displayThreadId,
+                  thread,
+                );
+                await handleSubmit(
+                  { text: answer, files: [] },
+                  { fromClarification: true },
+                );
+              })();
+            }}
             onEditResubmit={(text) => void handleSubmit({ text, files: [] })}
             onOpenArtifact={handleOpenMessageArtifact}
           />

frontend-web/src/position-roundtable/components/PositionNodeChat.tsx

@@ -16,6 +16,7 @@ import { MessageList } from "@/components/workspace/messages";
 import { useAgent } from "@/core/agents";
 import { useLocalSettings } from "@/core/settings";
 import {
+  stopActiveThreadBeforeClarificationReply,
   useEditMessage,
   useThreadStream,
   type ToolStartEvent,
@@ -852,6 +853,9 @@ export function PositionNodeChat({
         await sendMessage(boundThreadIdRef.current ?? draftThreadIdRef.current, message, {
           agent_id: node.agentId,
           task_external_context: taskExternalContext,
+          // Hard-cap outputs write_file to one deliverable per turn (weak models
+          // otherwise rewrite the same Markdown and loop). Action-plan is exempt.
+          position_artifact_cap: 1,
         });
       } catch (error) {
         autoPreviewRunArmedRef.current = false;
@@ -1006,9 +1010,15 @@ export function PositionNodeChat({
             // nodes own the actual stream. Route their answer through the
             // same submit path as the normal input so handoff context,
             // permissions and node lifecycle updates are all preserved.
-            onClarificationSubmit={(answer) =>
-              handleSubmit({ text: answer, files: [] })
-            }
+            onClarificationSubmit={(answer) => {
+              void (async () => {
+                await stopActiveThreadBeforeClarificationReply(
+                  boundThreadId ?? displayThreadId,
+                  thread,
+                );
+                await handleSubmit({ text: answer, files: [] });
+              })();
+            }}
             onEditResubmit={(text) => void handleSubmit({ text, files: [] })}
             onEditSave={handleSaveMessageEdit}
             messageContentOverrides={messageContentOverrides}

frontend-web/src/styles/globals.css

@@ -76,6 +76,26 @@
 
 @custom-variant dark (&:is(.dark *));
 
+@layer utilities {
+  .report-structure-detail-scrollbar::-webkit-scrollbar {
+    width: 6px;
+    height: 6px;
+  }
+
+  .report-structure-detail-scrollbar::-webkit-scrollbar-track {
+    background: transparent;
+  }
+
+  .report-structure-detail-scrollbar::-webkit-scrollbar-thumb {
+    background: #e2e8f0;
+    border-radius: 9999px;
+  }
+
+  .report-structure-detail-scrollbar::-webkit-scrollbar-thumb:hover {
+    background: #cbd5e1;
+  }
+}
+
 @theme {
   --font-sans:
     "Noto Sans S Chinese", "Noto Sans SC", "Source Han Sans SC", "思源黑体",