优化历史会话排序逻辑，按首条消息时间排序

src/components/chat/AgentHistoryPanel.test.tsx

@@ -33,8 +33,37 @@ describe("AgentHistoryPanel", () => {
     fireEvent.change(screen.getByPlaceholderText("请输入会话标题"), {
       target: { value: "新的会话标题" },
     });
-    fireEvent.click(screen.getByLabelText("确认修改历史会话标题"));
+    fireEvent.click(screen.getByLabelText("确认"));
 
     expect(onRenameSession).toHaveBeenCalledWith("session-1", "新的会话标题");
   });
+
+  it("orders history by the first message time instead of the latest update time", () => {
+    renderWithTheme(
+      <AgentHistoryPanel
+        sessions={[
+          {
+            id: "session-newer-update",
+            title: "较新的更新",
+            createdAt: new Date("2026-05-18T09:00:00+08:00").getTime(),
+            updatedAt: new Date("2026-05-19T12:00:00+08:00").getTime(),
+          },
+          {
+            id: "session-newer-first-message",
+            title: "较新的首条消息",
+            createdAt: new Date("2026-05-19T08:00:00+08:00").getTime(),
+            updatedAt: new Date("2026-05-19T08:30:00+08:00").getTime(),
+          },
+        ]}
+        onNewSession={jest.fn()}
+        onRenameSession={jest.fn()}
+        onSelectSession={jest.fn()}
+        onDeleteSession={jest.fn()}
+      />,
+    );
+
+    const sessionTitles = screen.getAllByText(/较新的/).map((element) => element.textContent);
+
+    expect(sessionTitles).toEqual(["较新的首条消息", "较新的更新"]);
+  });
 });

src/components/chat/AgentHistoryPanel.tsx

@@ -73,7 +73,6 @@ const getSessionGroupLabel = (timestamp: number) => {
 };
 
 export const AgentHistoryPanel = ({
-
   sessions,
   activeSessionId,
   isHydrating = false,
@@ -95,11 +94,25 @@ export const AgentHistoryPanel = ({
     return sessions.filter((session) => session.title.toLowerCase().includes(normalizedKeyword));
   }, [keyword, sessions]);
 
+  const sortedFilteredSessions = React.useMemo(
+    () =>
+      [...filteredSessions].sort((left, right) => {
+        const createdAtDiff = right.createdAt - left.createdAt;
+        if (createdAtDiff !== 0) return createdAtDiff;
+
+        const updatedAtDiff = right.updatedAt - left.updatedAt;
+        if (updatedAtDiff !== 0) return updatedAtDiff;
+
+        return right.id.localeCompare(left.id);
+      }),
+    [filteredSessions],
+  );
+
   const groupedSessions = React.useMemo(() => {
     const groups = new Map<string, ChatSessionSummary[]>();
 
-    filteredSessions.forEach((session) => {
-      const label = getSessionGroupLabel(session.updatedAt);
+    sortedFilteredSessions.forEach((session) => {
+      const label = getSessionGroupLabel(session.createdAt);
       const existing = groups.get(label);
       if (existing) {
         existing.push(session);
@@ -109,7 +122,7 @@ export const AgentHistoryPanel = ({
     });
 
     return Array.from(groups.entries());
-  }, [filteredSessions]);
+  }, [sortedFilteredSessions]);
 
   const pendingDeleteSession = filteredSessions.find(
     (session) => session.id === pendingDeleteSessionId,
@@ -390,7 +403,7 @@ export const AgentHistoryPanel = ({
                                     {session.title}
                                   </Typography>
                                   <Typography variant="caption" color="text.secondary" sx={{ mt: 0.5, display: "block" }}>
-                                    {formatRelativeDate(session.updatedAt)}
+                                    {formatRelativeDate(session.createdAt)}
                                   </Typography>
                                 </Box>
                               )}

src/components/chat/chatStorage.ts

@@ -51,6 +51,28 @@ const sanitizeMessages = (messages: Message[] | undefined) =>
 const sanitizeBranchGroups = (branchGroups: BranchGroup[] | undefined) =>
   Array.isArray(branchGroups) ? cloneBranchGroups(branchGroups) : [];
 
+const hasChatContent = (state: {
+  messages: Message[];
+  branchGroups: BranchGroup[];
+  sessionId?: string;
+}) =>
+  state.messages.length > 0 ||
+  state.branchGroups.length > 0 ||
+  Boolean(state.sessionId);
+
+const compareSessionsByAnchorTime = (
+  left: Pick<ChatSessionRecord, "id" | "createdAt" | "updatedAt">,
+  right: Pick<ChatSessionRecord, "id" | "createdAt" | "updatedAt">,
+) => {
+  const createdAtDiff = right.createdAt - left.createdAt;
+  if (createdAtDiff !== 0) return createdAtDiff;
+
+  const updatedAtDiff = right.updatedAt - left.updatedAt;
+  if (updatedAtDiff !== 0) return updatedAtDiff;
+
+  return right.id.localeCompare(left.id);
+};
+
 const toLoadedChatState = (session: ChatSessionRecord | undefined): LoadedChatState => {
   if (!session) return emptyLoadedChatState();
   return {
@@ -131,7 +153,7 @@ const getLatestSession = async () => {
   const db = await getDb();
   const sessions = await db.getAll(SESSION_STORE);
   if (sessions.length === 0) return undefined;
-  return sessions.sort((left, right) => right.updatedAt - left.updatedAt)[0];
+  return sessions.sort(compareSessionsByAnchorTime)[0];
 };
 
 const migrateLegacyLocalStorage = async () => {
@@ -215,10 +237,7 @@ export const saveActiveChatState = async (
 ): Promise<string | undefined> => {
   if (typeof window === "undefined") return state.storageSessionId;
 
-  const hasContent =
-    state.messages.length > 0 ||
-    state.branchGroups.length > 0 ||
-    Boolean(state.sessionId);
+  const hasContent = hasChatContent(state);
 
   const db = await getDb();
   const existingSession = state.storageSessionId
@@ -241,11 +260,15 @@ export const saveActiveChatState = async (
   const storageSessionId = state.storageSessionId ?? createId();
   const preferredTitle = state.title?.trim();
   const finalTitle = preferredTitle || existingSession?.title || "新对话";
+  const shouldAnchorCreatedAtToFirstMessage =
+    Boolean(existingSession) && !hasChatContent(existingSession) && hasContent;
   const nextRecord: ChatSessionRecord = {
     id: storageSessionId,
     title: finalTitle,
     isTitleManuallyEdited: state.isTitleManuallyEdited ?? existingSession?.isTitleManuallyEdited ?? false,
-    createdAt: existingSession?.createdAt ?? now,
+    createdAt: shouldAnchorCreatedAtToFirstMessage
+      ? now
+      : existingSession?.createdAt ?? now,
     updatedAt: now,
     sessionId: state.sessionId,
     messages: sanitizeMessages(state.messages),
@@ -268,9 +291,7 @@ export const listChatSessions = async (): Promise<ChatSessionSummary[]> => {
 
   const db = await getDb();
   const sessions = await db.getAll(SESSION_STORE);
-  return sessions
-    .sort((left, right) => right.updatedAt - left.updatedAt)
-    .map(toSessionSummary);
+  return sessions.sort(compareSessionsByAnchorTime).map(toSessionSummary);
 };
 
 export const updateChatSessionTitle = async (
@@ -353,9 +374,7 @@ export const deleteChatSession = async (sessionId: string): Promise<string | und
   await db.delete(SESSION_STORE, sessionId);
 
   const remainingSessions = await db.getAll(SESSION_STORE);
-  const nextActiveSession = remainingSessions.sort(
-    (left, right) => right.updatedAt - left.updatedAt,
-  )[0];
+  const nextActiveSession = remainingSessions.sort(compareSessionsByAnchorTime)[0];
   const meta = await getMeta();
 
   await setMeta({