优化历史会话排序逻辑，按首条消息时间排序

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({