重构聊天会话标题管理，支持首轮对话更新

src/components/chat/chatStorage.ts

@@ -68,14 +68,6 @@ const toSessionSummary = (session: ChatSessionRecord): ChatSessionSummary => ({
   updatedAt: session.updatedAt,
 });
 
-const buildSessionTitle = (messages: Message[]) => {
-  const firstUserMessage = messages.find((message) => message.role === "user");
-  if (!firstUserMessage) return "新对话";
-  const title = firstUserMessage.content.replace(/\s+/g, " ").trim();
-  if (!title) return "新对话";
-  return title.length > 24 ? `${title.slice(0, 24)}...` : title;
-};
-
 const getDb = () =>
   openDB<ChatDB>(CHAT_DB_NAME, CHAT_DB_VERSION, {
     upgrade(db) {
@@ -170,7 +162,7 @@ const migrateLegacyLocalStorage = async () => {
   const now = Date.now();
   const sessionRecord: ChatSessionRecord = {
     id: createId(),
-    title: buildSessionTitle(legacyState.messages),
+    title: "新对话",
     createdAt: now,
     updatedAt: now,
     sessionId: legacyState.sessionId,
@@ -244,9 +236,8 @@ export const saveActiveChatState = async (
 
   const now = Date.now();
   const storageSessionId = state.storageSessionId ?? createId();
-  const computedTitle = buildSessionTitle(state.messages);
   const preferredTitle = state.title?.trim();
-  const finalTitle = preferredTitle || computedTitle;
+  const finalTitle = preferredTitle || existingSession?.title || "新对话";
   const nextRecord: ChatSessionRecord = {
     id: storageSessionId,
     title: finalTitle,
@@ -278,6 +269,26 @@ export const listChatSessions = async (): Promise<ChatSessionSummary[]> => {
     .map(toSessionSummary);
 };
 
+export const updateChatSessionTitle = async (
+  storageSessionId: string,
+  title: string,
+): Promise<void> => {
+  if (typeof window === "undefined") return;
+
+  const normalizedTitle = title.trim();
+  if (!normalizedTitle) return;
+
+  const db = await getDb();
+  const session = await db.get(SESSION_STORE, storageSessionId);
+  if (!session) return;
+
+  await db.put(SESSION_STORE, {
+    ...session,
+    title: normalizedTitle,
+    updatedAt: Date.now(),
+  });
+};
+
 export const createEmptyChatSession = async (): Promise<LoadedChatState> => {
   if (typeof window === "undefined") return emptyLoadedChatState();
 

src/components/chat/hooks/useAgentChatSession.ts

@@ -25,6 +25,7 @@ import {
   loadActiveChatState,
   loadChatSessionById,
   saveActiveChatState,
+  updateChatSessionTitle,
 } from "../chatStorage";
 
 type UseAgentChatSessionOptions = {
@@ -110,6 +111,7 @@ export const useAgentChatSession = ({
   const abortRef = useRef<AbortController | null>(null);
   const sessionIdRef = useRef<string | undefined>(undefined);
   const cancelPromiseRef = useRef<Promise<void> | null>(null);
+  const titleUpdateNonceRef = useRef(0);
 
   useEffect(() => {
     sessionIdRef.current = sessionId;
@@ -130,6 +132,7 @@ export const useAgentChatSession = ({
         sessionIdRef.current = loadedState.sessionId;
         hydrationCompletedRef.current = true;
         hydrationNonceRef.current += 1;
+        titleUpdateNonceRef.current += 1;
 
         setMessages(loadedState.messages);
         setSessionTitle(loadedState.title);
@@ -308,6 +311,19 @@ export const useAgentChatSession = ({
               const nextTitle = event.title.trim();
               if (nextTitle) {
                 setSessionTitle(nextTitle);
+                const currentStorageSessionId = storageSessionIdRef.current;
+                if (currentStorageSessionId) {
+                  const currentNonce = ++titleUpdateNonceRef.current;
+                  void updateChatSessionTitle(currentStorageSessionId, nextTitle)
+                    .then(() => listChatSessions())
+                    .then((sessions) => {
+                      if (titleUpdateNonceRef.current !== currentNonce) return;
+                      setChatSessions(sessions);
+                    })
+                    .catch((error) => {
+                      console.error("[GlobalChatbox] Failed to persist session title:", error);
+                    });
+                }
               }
             } else if (event.type === "done") {
               setMessages((prev) =>
@@ -431,6 +447,7 @@ export const useAgentChatSession = ({
     setSessionId(undefined);
     sessionIdRef.current = undefined;
     storageSessionIdRef.current = undefined;
+    titleUpdateNonceRef.current += 1;
     setIsStreaming(false);
   }, []);
 
@@ -445,6 +462,7 @@ export const useAgentChatSession = ({
     const sessions = await listChatSessions();
 
     hydrationNonceRef.current += 1;
+    titleUpdateNonceRef.current += 1;
     storageSessionIdRef.current = newState.storageSessionId;
     sessionIdRef.current = newState.sessionId;
     setMessages(newState.messages);
@@ -469,6 +487,7 @@ export const useAgentChatSession = ({
         ]);
 
         hydrationNonceRef.current += 1;
+        titleUpdateNonceRef.current += 1;
         storageSessionIdRef.current = nextState.storageSessionId;
         sessionIdRef.current = nextState.sessionId;
         setBranchTransition(null);
@@ -501,6 +520,7 @@ export const useAgentChatSession = ({
 
         if (!nextActiveSessionId) {
           hydrationNonceRef.current += 1;
+          titleUpdateNonceRef.current += 1;
           storageSessionIdRef.current = undefined;
           sessionIdRef.current = undefined;
           setBranchTransition(null);
@@ -517,6 +537,7 @@ export const useAgentChatSession = ({
           listChatSessions(),
         ]);
         hydrationNonceRef.current += 1;
+        titleUpdateNonceRef.current += 1;
         storageSessionIdRef.current = nextState.storageSessionId;
         sessionIdRef.current = nextState.sessionId;
         setBranchTransition(null);