diff --git a/apps/ai-game-creator-shell/src/view/project-development/chat/DirectProjectChatView.tsx b/apps/ai-game-creator-shell/src/view/project-development/chat/DirectProjectChatView.tsx
index e10829c5f..b914c8db9 100644
--- a/apps/ai-game-creator-shell/src/view/project-development/chat/DirectProjectChatView.tsx
+++ b/apps/ai-game-creator-shell/src/view/project-development/chat/DirectProjectChatView.tsx
@@ -1,15 +1,12 @@
-import type { UIEventHandler } from 'react';
 import type { Ref } from 'react';
 import {
   useCallback,
   useEffect,
   useImperativeHandle,
   useMemo,
-  useRef,
   useState,
 } from 'react';
 
-import { AGENT_CHAT_SCROLL_BOTTOM_THRESHOLD } from '../../../app/constants';
 import { claimInitialTurnForPage } from '../../../app/initialTurnClaims';
 import type { PendingUiConfirmation } from '../../../app/types';
 import { projectNameFromPath } from '../../../features/agent-runtime';
@@ -106,8 +103,6 @@ export function DirectProjectChatView({
 }: DirectProjectChatViewProps) {
   const { assets, projectId, refresh, versions } =
     useDirectProjectManifest(projectPath);
-  const messagesRef = useRef<HTMLDivElement | null>(null);
-  const shouldFollowLatestRef = useRef(true);
   const [runtimeNotice, setRuntimeNotice] = useState('');
   const [settingsOpen, setSettingsOpen] = useState(false);
   const [approvalOpen, setApprovalOpen] = useState(false);
@@ -137,8 +132,11 @@ export function DirectProjectChatView({
     directEntries,
     directTurnRunning,
     directTurnStartedAt,
+    historyError,
     historyHasMore,
+    historyLoading,
     loadEarlierHistory,
+    retryEarlierHistory,
     localMessages,
     pendingTurns,
     startInitialTurn,
@@ -197,7 +195,6 @@ export function DirectProjectChatView({
       initialTurn.content,
       directCodexConversationMessageId(clientTurnId, 'user'),
     );
-    shouldFollowLatestRef.current = true;
     startInitialTurn({
       clientTurnId,
       ...(initialTurn.creationType
@@ -209,28 +206,12 @@ export function DirectProjectChatView({
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [turnStatus.displayBusy, initialTurn, projectId, projectPath]);
 
-  useEffect(() => {
-    if (!shouldFollowLatestRef.current) return;
-    const list = messagesRef.current;
-    if (list) list.scrollTop = list.scrollHeight;
-  }, [directEntries, localMessages]);
-
   useImperativeHandle(ref, () => ({
     announce: (text: string) => {
       appendLocalMessage({ role: 'assistant', text, updatedAt: Date.now() });
     },
   }));
 
-  const handleScroll: UIEventHandler<HTMLDivElement> = (event) => {
-    const list = event.currentTarget;
-    shouldFollowLatestRef.current =
-      list.scrollHeight - list.scrollTop - list.clientHeight <=
-      AGENT_CHAT_SCROLL_BOTTOM_THRESHOLD;
-    if (historyHasMore && list.scrollTop <= 24) {
-      void loadEarlierHistory();
-    }
-  };
-
   return (
     <section
       className="project-chat-surface is-direct-codex"
@@ -245,12 +226,13 @@ export function DirectProjectChatView({
         />
         <DirectProjectConversation
           turns={directTurns}
-          messagesRef={messagesRef}
           historyHasMore={historyHasMore}
+          historyLoading={historyLoading}
+          historyError={historyError}
           turnInFlight={turnStatus.displayBusy}
           activeTurnStartedAt={activeTurnStartedAt}
           onLoadEarlierHistory={() => void loadEarlierHistory()}
-          onScroll={handleScroll}
+          onRetryEarlierHistory={() => void retryEarlierHistory()}
         />
         {pendingConfirmation &&
         onConfirmConfirmation &&
diff --git a/apps/ai-game-creator-shell/src/view/project-development/chat/components/DirectProjectConversation/DirectProjectConversation.tsx b/apps/ai-game-creator-shell/src/view/project-development/chat/components/DirectProjectConversation/DirectProjectConversation.tsx
index b9595d9ee..4aa29a5c2 100644
--- a/apps/ai-game-creator-shell/src/view/project-development/chat/components/DirectProjectConversation/DirectProjectConversation.tsx
+++ b/apps/ai-game-creator-shell/src/view/project-development/chat/components/DirectProjectConversation/DirectProjectConversation.tsx
@@ -1,28 +1,40 @@
-import type { RefObject, UIEventHandler } from 'react';
-
 import { AgentMessageContent } from '../../../../../../../../packages/shared/src/components/AgentMessageContent';
 import { useLiveNow } from '../../../../../features/project-workspace/useLiveNow';
 import type { DirectChatTurn } from '../../conversation/directTurnPresentation';
 import { formatTurnDuration } from '../ToolCallGroup/toolCallGroupPresentation';
+import {
+  DirectProjectHistoryErrorRow,
+  DirectProjectHistoryLoadingRow,
+} from './DirectProjectHistoryRow';
+import { DirectProjectScrollToBottomCapsule } from './DirectProjectScrollToBottomCapsule';
 import { DirectProjectTurn } from './DirectProjectTurn';
+import { useConversationScroll } from './useConversationScroll';
 
 /**
- * 会话区：回合列表、更早历史入口和运行中过程卡。
+ * 会话区：回合列表、更早历史的加载 / 失败行与运行中过程卡。
+ *
+ * **滚动归这一层所有**：贴底跟随、更早历史的自动加载、前插锚点与回到底部胶囊都在
+ * `useConversationScroll` 里，视图不再自己持 `messagesRef` / `shouldFollowLatestRef` /
+ * `handleScroll`——三套补偿写同一份 `scrollTop`，分开持有必然互相覆盖。
  *
  * 回合来自 DirectProject 自己的投影；这里不读历史、不发回合，只把容器给的状态渲染出来。
  */
 export function DirectProjectConversation({
   turns,
-  messagesRef,
   historyHasMore,
+  historyLoading,
+  historyError,
   turnInFlight,
   activeTurnStartedAt,
   onLoadEarlierHistory,
-  onScroll,
+  onRetryEarlierHistory,
 }: {
   turns: DirectChatTurn[];
-  messagesRef: RefObject<HTMLDivElement | null>;
   historyHasMore: boolean;
+  /** 更早历史正在读：驱动顶部加载行（延迟 150ms 才挂载）。 */
+  historyLoading: boolean;
+  /** 更早历史读取失败：非空即挂起自动加载，只留内联错误行的重试。 */
+  historyError: string | null;
   /**
    * 这一轮在飞吗：`DirectProjectTurnStatus.displayBusy`（本地命令在飞 ∪ 原生已确认在跑）。
    *
@@ -33,28 +45,48 @@ export function DirectProjectConversation({
   turnInFlight: boolean;
   activeTurnStartedAt: number;
   onLoadEarlierHistory: () => void;
-  onScroll: UIEventHandler<HTMLDivElement>;
+  onRetryEarlierHistory: () => void;
 }) {
+  const {
+    listRef,
+    onScroll,
+    onToggleCapture,
+    scrollToBottom,
+    showScrollToBottom,
+    scrollToBottomLabel,
+    showHistoryLoading,
+  } = useConversationScroll({
+    turns,
+    historyHasMore,
+    historyLoading,
+    historyError,
+    turnInFlight,
+    onLoadEarlierHistory,
+  });
   return (
     <>
+      {/* `overflow-anchor: none`：关掉浏览器原生 scroll anchoring，前插与展开的补偿只走
+          `useConversationScroll` 这一份，避免两套补偿在同一帧里互相抵消。 */}
       <div
-        ref={messagesRef}
-        className="message-list project-chat-message-list"
+        ref={listRef}
+        className="message-list project-chat-message-list [overflow-anchor:none]"
         aria-label="陶泥儿消息"
         onScroll={onScroll}
+        onClickCapture={onToggleCapture}
       >
-        {historyHasMore ? (
-          <button
-            type="button"
-            className="message-history-more"
-            onClick={onLoadEarlierHistory}
-          >
-            显示更早的对话
-          </button>
+        {showHistoryLoading ? <DirectProjectHistoryLoadingRow /> : null}
+        {historyError ? (
+          <DirectProjectHistoryErrorRow onRetry={onRetryEarlierHistory} />
         ) : null}
         {turns.map((turn) => (
           <DirectProjectTurn key={turn.key} turn={turn} />
         ))}
+        {showScrollToBottom ? (
+          <DirectProjectScrollToBottomCapsule
+            label={scrollToBottomLabel}
+            onClick={scrollToBottom}
+          />
+        ) : null}
       </div>
       {turnInFlight ? (
         <AgentMessageContent
diff --git a/apps/ai-game-creator-shell/src/view/project-development/chat/components/DirectProjectConversation/DirectProjectHistoryRow.tsx b/apps/ai-game-creator-shell/src/view/project-development/chat/components/DirectProjectConversation/DirectProjectHistoryRow.tsx
new file mode 100644
index 000000000..66672ce56
--- /dev/null
+++ b/apps/ai-game-creator-shell/src/view/project-development/chat/components/DirectProjectConversation/DirectProjectHistoryRow.tsx
@@ -0,0 +1,54 @@
+import { Loader2 } from 'lucide-react';
+
+import {
+  HISTORY_ERROR_TEXT,
+  HISTORY_LOADING_TEXT,
+  HISTORY_RETRY_TEXT,
+} from './conversationScrollPolicy';
+
+/**
+ * 列表顶部的两行历史状态条（加载中 / 加载失败）。
+ *
+ * 它们都排在**最旧一条回合之上**——内容将出现的位置，而不是浮在视口上——所以不影响下面消息的
+ * 可读性；前插期间的 `scrollTop` 补偿由 `useConversationScroll` 负责，这两行本身只管一层皮。
+ *
+ * 按钮删掉之后，「加载更早对话失败」这行是用户唯一还能自己补救的入口：它一直留到重试成功，
+ * 不自动消失。
+ */
+
+/** 加载更早历史时的旋转圈。按需挂载，是否显示由 `useDelayedFlag` 决定。 */
+export function DirectProjectHistoryLoadingRow() {
+  return (
+    <p
+      className="flex items-center justify-center gap-1.5 py-2 text-xs text-[color:var(--platform-text-muted)]"
+      role="status"
+      aria-live="polite"
+    >
+      <Loader2 className="animate-spin" size={14} aria-hidden="true" />
+      {HISTORY_LOADING_TEXT}
+    </p>
+  );
+}
+
+/** 自动加载挂起后的内联错误行：重试是唯一的手动出路，成功前一直留在列表顶部。 */
+export function DirectProjectHistoryErrorRow({
+  onRetry,
+}: {
+  onRetry: () => void;
+}) {
+  return (
+    <p
+      className="flex items-center justify-center gap-2 py-2 text-xs text-[color:var(--platform-button-danger-text)]"
+      role="alert"
+    >
+      {HISTORY_ERROR_TEXT}
+      <button
+        type="button"
+        className="rounded-full border border-[color:var(--platform-subpanel-border)] px-2 py-0.5 text-xs text-[color:var(--platform-text-strong)] transition hover:bg-[var(--platform-neutral-bg)]"
+        onClick={onRetry}
+      >
+        {HISTORY_RETRY_TEXT}
+      </button>
+    </p>
+  );
+}
diff --git a/apps/ai-game-creator-shell/src/view/project-development/chat/components/DirectProjectConversation/DirectProjectScrollToBottomCapsule.tsx b/apps/ai-game-creator-shell/src/view/project-development/chat/components/DirectProjectConversation/DirectProjectScrollToBottomCapsule.tsx
new file mode 100644
index 000000000..cbf78edf9
--- /dev/null
+++ b/apps/ai-game-creator-shell/src/view/project-development/chat/components/DirectProjectConversation/DirectProjectScrollToBottomCapsule.tsx
@@ -0,0 +1,29 @@
+import { ArrowDown } from 'lucide-react';
+
+/**
+ * 底部居中的「回到底部」胶囊。
+ *
+ * 用 `sticky bottom-*` 而不是浮层：工作台里 `.project-chat-conversation` 是 `display: block`
+ * 加 `height: 100%` 的几何，在列表外套一层定位容器会把列表的 `height: 100%` 塌成内容高度；
+ * 粘在列表内部的胶囊零结构改动，两块宿主（工作台侧栏与独立页面）都能拿到。
+ *
+ * 显隐与文案由调用方决定（距底超过阈值才出现；不跟随时来了新回复就换文案），这里只负责表现。
+ */
+export function DirectProjectScrollToBottomCapsule({
+  label,
+  onClick,
+}: {
+  label: string;
+  onClick: () => void;
+}) {
+  return (
+    <button
+      type="button"
+      className="sticky bottom-3 z-10 mx-auto mt-1 flex w-fit items-center gap-1.5 rounded-full border border-[color:var(--platform-subpanel-border)] bg-[var(--platform-neutral-bg)] px-3 py-1.5 text-xs font-medium text-[color:var(--platform-text-strong)] shadow-[0_6px_18px_rgba(24,32,47,0.16)] backdrop-blur"
+      onClick={onClick}
+    >
+      <ArrowDown size={13} aria-hidden="true" />
+      {label}
+    </button>
+  );
+}
diff --git a/apps/ai-game-creator-shell/src/view/project-development/chat/components/DirectProjectConversation/conversationScrollPolicy.ts b/apps/ai-game-creator-shell/src/view/project-development/chat/components/DirectProjectConversation/conversationScrollPolicy.ts
index 845aec2c7..af8d578c6 100644
--- a/apps/ai-game-creator-shell/src/view/project-development/chat/components/DirectProjectConversation/conversationScrollPolicy.ts
+++ b/apps/ai-game-creator-shell/src/view/project-development/chat/components/DirectProjectConversation/conversationScrollPolicy.ts
@@ -112,3 +112,18 @@ export function shouldFillViewport(
 export function scrollToBottomLabel(hasNewReply: boolean): string {
   return hasNewReply ? SCROLL_TO_BOTTOM_UNREAD_TEXT : SCROLL_TO_BOTTOM_TEXT;
 }
+
+/**
+ * 「有新回复」的判据：最后一轮的**终态内容**（用户气泡 + 助手最终答复）指纹。
+ *
+ * 只取最后一轮的数量，不取全部回合：更早历史是往前插的，用全量指纹会把「加载更早历史成功」
+ * 误报成「有新回复」。同一轮里过程块继续增长也不算——用户要的是"有没有新内容可说"，
+ * 不是"这一轮跑了多久"。
+ */
+export function terminalContentSignature(
+  turns: readonly { key: string; users: unknown[]; finals: unknown[] }[],
+): string {
+  const last = turns[turns.length - 1];
+  if (!last) return '';
+  return `${last.key}:${last.users.length}:${last.finals.length}`;
+}
diff --git a/apps/ai-game-creator-shell/src/view/project-development/chat/components/DirectProjectConversation/useConversationScroll.ts b/apps/ai-game-creator-shell/src/view/project-development/chat/components/DirectProjectConversation/useConversationScroll.ts
new file mode 100644
index 000000000..cb3e2e7e8
--- /dev/null
+++ b/apps/ai-game-creator-shell/src/view/project-development/chat/components/DirectProjectConversation/useConversationScroll.ts
@@ -0,0 +1,269 @@
+import {
+  type MouseEventHandler,
+  type RefObject,
+  type UIEventHandler,
+  useCallback,
+  useEffect,
+  useRef,
+  useState,
+} from 'react';
+
+import type { DirectChatTurn } from '../../conversation/directTurnPresentation';
+import {
+  type ConversationTurnAnchor,
+  readTopVisibleTurnAnchor,
+  restoreTurnAnchor,
+} from './conversationScrollAnchor';
+import {
+  HISTORY_LOADING_INDICATOR_DELAY_MS,
+  isNearBottom,
+  readConversationListMetrics,
+  scrollToBottomLabel,
+  shouldFillViewport,
+  shouldLoadEarlierOnScroll,
+  terminalContentSignature,
+} from './conversationScrollPolicy';
+import {
+  type ConversationToggleFold,
+  freezeToggleHead,
+  resolveToggleHead,
+} from './conversationToggleReveal';
+import { useDelayedFlag } from './useDelayedFlag';
+
+/**
+ * 会话列表的滚动所有权：跟随最新、更早历史自动加载、前插锚定、折叠补偿与回到底部胶囊。
+ *
+ * 这一层只碰列表这一个滚动容器，读的几何全部来自真实布局；所有判据（阈值、文案、合并门）
+ * 都在 `conversationScrollPolicy.ts` 的纯函数里，策略改动不需要动这里的状态机。契约见
+ * `docs/adr/【ADR】DirectProject对话滚动与历史自动加载-2026-10-02.md`。
+ *
+ * 为什么集中在一处：贴底跟随、前插保锚点、展开补偿是同一份 `scrollTop` 上的三套补偿，
+ * 分散到视图里就会互相覆盖（同一帧里谁后写谁赢，表现为间歇性跳动）。
+ */
+export type ConversationScrollOptions = {
+  /** 已渲染的回合投影：内容变化既驱动贴底，也驱动「有新回复」。 */
+  turns: readonly DirectChatTurn[];
+  historyHasMore: boolean;
+  historyLoading: boolean;
+  historyError: string | null;
+  /** 这一轮在飞（`DirectProjectTurnStatus.displayBusy`）：新回合开始要强制回到最新。 */
+  turnInFlight: boolean;
+  onLoadEarlierHistory: () => void;
+};
+
+export type ConversationScrollBinding = {
+  listRef: RefObject<HTMLDivElement | null>;
+  onScroll: UIEventHandler<HTMLDivElement>;
+  /** 点击捕获：记录折叠头展开前的屏幕位置，供布局变化后的补偿用。 */
+  onToggleCapture: MouseEventHandler<HTMLDivElement>;
+  scrollToBottom: () => void;
+  showScrollToBottom: boolean;
+  scrollToBottomLabel: string;
+  /** 延迟 150ms 后的加载态：直接挂载会在本地瞬时读取时闪一下。 */
+  showHistoryLoading: boolean;
+};
+
+function scrollListToBottom(
+  list: HTMLDivElement | null,
+  behavior: ScrollBehavior,
+): void {
+  if (!list) return;
+  if (behavior === 'smooth' && typeof list.scrollTo === 'function') {
+    list.scrollTo({ top: list.scrollHeight, behavior });
+    return;
+  }
+  list.scrollTop = list.scrollHeight;
+}
+
+export function useConversationScroll({
+  turns,
+  historyHasMore,
+  historyLoading,
+  historyError,
+  turnInFlight,
+  onLoadEarlierHistory,
+}: ConversationScrollOptions): ConversationScrollBinding {
+  const listRef = useRef<HTMLDivElement | null>(null);
+  /** 跟随时任何高度变化都贴底；用户离开底部（或点胶囊）即翻转。 */
+  const followLatestRef = useRef(true);
+  const [atBottom, setAtBottom] = useState(true);
+  const [hasNewReply, setHasNewReply] = useState(false);
+  /** 前插时要保住的顶部可见回合；每次滚动与补偿后刷新。 */
+  const preserveAnchorRef = useRef<ConversationTurnAnchor | null>(null);
+  /** 刚刚展开 / 收起的折叠头；只被下一次布局补偿消费一次。 */
+  const foldRef = useRef<ConversationToggleFold | null>(null);
+  const turnInFlightRef = useRef(turnInFlight);
+  const terminalSignatureRef = useRef(terminalContentSignature(turns));
+  /**
+   * 更早历史是否正在读：加载期间锚点保持冻结——加载行挂载、历史合并这些回调都还原同一个
+   * 锚点，加载结束后的下一次补偿才刷新（见 ADR 第 2 条），否则两次补偿会各按各的基准还原。
+   */
+  const historyLoadingRef = useRef(historyLoading);
+  useEffect(() => {
+    historyLoadingRef.current = historyLoading;
+  }, [historyLoading]);
+
+  const showHistoryLoading = useDelayedFlag(
+    historyLoading,
+    HISTORY_LOADING_INDICATOR_DELAY_MS,
+  );
+
+  /**
+   * 加载入口过一手 ref：调用方（视图）每次渲染都会给一个新函数，直接进依赖数组会让填充视口的
+   * 判据每次渲染都重跑一遍；这里只认最后一次给进来的那一个。
+   */
+  const loadEarlierRef = useRef(onLoadEarlierHistory);
+  useEffect(() => {
+    loadEarlierRef.current = onLoadEarlierHistory;
+  }, [onLoadEarlierHistory]);
+  const loadEarlier = useCallback(() => {
+    loadEarlierRef.current();
+  }, []);
+
+  /**
+   * 布局变化后的补偿：跟随时贴底；否则优先冻结刚展开的折叠头，再退到前插锚点。
+   *
+   * 顺序不能颠倒：展开的补偿比锚点更精确（锚点只保证"某条回合"不动，冻结保证"你点的那个头"
+   * 不动），而锚点还原是前插场景唯一能用的手段。
+   */
+  const compensateLayout = useCallback(() => {
+    const list = listRef.current;
+    if (!list) return;
+
+    if (followLatestRef.current) {
+      scrollListToBottom(list, 'auto');
+      return;
+    }
+
+    const fold = foldRef.current;
+    if (fold) {
+      foldRef.current = null;
+      if (freezeToggleHead(list, fold)) {
+        // 补偿后刷新锚点：下一个回调（一次展开可能触发多次）落到同一条回合上，不会再动。
+        preserveAnchorRef.current = readTopVisibleTurnAnchor(list);
+        return;
+      }
+    }
+
+    const anchor = preserveAnchorRef.current;
+    if (!anchor) return;
+    if (restoreTurnAnchor(list, anchor)) {
+      // 加载期间不刷新：整段加载里的每次补偿都还原同一个锚点，加载结束后再重起一个。
+      if (!historyLoadingRef.current) {
+        preserveAnchorRef.current = readTopVisibleTurnAnchor(list);
+      }
+      return;
+    }
+    // 锚点对应的块已经不在了（折叠态换过结构）：拿当前位置重新起锚，别用过期偏移。
+    preserveAnchorRef.current = readTopVisibleTurnAnchor(list);
+  }, []);
+
+  // 内容变化：跟随时贴底；不跟随时只在**终态内容**增加时点亮「有新回复」。
+  useEffect(() => {
+    const signature = terminalContentSignature(turns);
+    const gainedTerminalContent = signature !== terminalSignatureRef.current;
+    terminalSignatureRef.current = signature;
+    if (followLatestRef.current) {
+      scrollListToBottom(listRef.current, 'auto');
+      return;
+    }
+    if (gainedTerminalContent) setHasNewReply(true);
+  }, [turns]);
+
+  // 观察列表的直接子元素：展开 / 收起、流式正文增长、图片撑高、历史前插都只有这一个入口。
+  // 子元素增删（回合追加、加载行挂卸）由 MutationObserver 触发重订阅。
+  useEffect(() => {
+    const list = listRef.current;
+    if (!list || typeof ResizeObserver === 'undefined') return undefined;
+
+    let observer: ResizeObserver | null = null;
+    const subscribe = () => {
+      observer?.disconnect();
+      observer = new ResizeObserver(() => compensateLayout());
+      for (const child of Array.from(list.children)) {
+        observer.observe(child);
+      }
+    };
+    subscribe();
+    const mutations = new MutationObserver(subscribe);
+    mutations.observe(list, { childList: true });
+
+    return () => {
+      mutations.disconnect();
+      observer?.disconnect();
+    };
+  }, [compensateLayout]);
+
+  // 新一回合开始（假 → 真）强制恢复跟随：用户上一轮跑完时停在中途，这一轮不该再让他手动滚。
+  useEffect(() => {
+    const started = turnInFlight && !turnInFlightRef.current;
+    turnInFlightRef.current = turnInFlight;
+    if (!started) return;
+    followLatestRef.current = true;
+    setAtBottom(true);
+    setHasNewReply(false);
+    scrollListToBottom(listRef.current, 'auto');
+  }, [turnInFlight]);
+
+  // 填充视口：首帧之后内容还没铺满，就继续往前拉，直到铺满或没有更早历史。
+  // 依赖 `turns` 而不是定时器：每次加载落一批新回合就再判一次，同一条链路自己收敛。
+  useEffect(() => {
+    const list = listRef.current;
+    if (!list) return;
+    const metrics = readConversationListMetrics(list);
+    if (
+      !shouldFillViewport(metrics, {
+        historyHasMore,
+        historyLoading,
+        historyError,
+      })
+    ) {
+      return;
+    }
+    loadEarlier();
+  }, [historyError, historyHasMore, historyLoading, loadEarlier, turns]);
+
+  const onScroll: UIEventHandler<HTMLDivElement> = (event) => {
+    const list = event.currentTarget;
+    const metrics = readConversationListMetrics(list);
+    const nearBottom = isNearBottom(metrics);
+    followLatestRef.current = nearBottom;
+    setAtBottom(nearBottom);
+    if (nearBottom) setHasNewReply(false);
+    else preserveAnchorRef.current = readTopVisibleTurnAnchor(list);
+
+    if (
+      shouldLoadEarlierOnScroll(metrics, {
+        historyHasMore,
+        historyLoading,
+        historyError,
+      })
+    ) {
+      loadEarlier();
+    }
+  };
+
+  const onToggleCapture: MouseEventHandler<HTMLDivElement> = (event) => {
+    const list = listRef.current;
+    const head = resolveToggleHead(event.target as Element | null);
+    if (!list || !head || !list.contains(head)) return;
+    foldRef.current = { head, headTop: head.getBoundingClientRect().top };
+  };
+
+  const scrollToBottom = useCallback(() => {
+    followLatestRef.current = true;
+    setAtBottom(true);
+    setHasNewReply(false);
+    scrollListToBottom(listRef.current, 'smooth');
+  }, []);
+
+  return {
+    listRef,
+    onScroll,
+    onToggleCapture,
+    scrollToBottom,
+    showScrollToBottom: !atBottom,
+    scrollToBottomLabel: scrollToBottomLabel(hasNewReply),
+    showHistoryLoading,
+  };
+}