重构会话标题编辑和删除确认逻辑；重构历史会话时间记录

src/components/chat/chatStorage.ts

@@ -51,6 +51,17 @@ const sanitizeMessages = (messages: Message[] | undefined) =>
 const sanitizeBranchGroups = (branchGroups: BranchGroup[] | undefined) =>
   Array.isArray(branchGroups) ? cloneBranchGroups(branchGroups) : [];
 
+const serializeConversationState = (state: {
+  messages: Message[];
+  branchGroups: BranchGroup[];
+  sessionId?: string;
+}) =>
+  JSON.stringify({
+    messages: sanitizeMessages(state.messages),
+    branchGroups: sanitizeBranchGroups(state.branchGroups),
+    sessionId: state.sessionId ?? null,
+  });
+
 const hasChatContent = (state: {
   messages: Message[];
   branchGroups: BranchGroup[];
@@ -260,6 +271,9 @@ export const saveActiveChatState = async (
   const storageSessionId = state.storageSessionId ?? createId();
   const preferredTitle = state.title?.trim();
   const finalTitle = preferredTitle || existingSession?.title || "新对话";
+  const hasContentChanged =
+    !existingSession ||
+    serializeConversationState(existingSession) !== serializeConversationState(state);
   const shouldAnchorCreatedAtToFirstMessage =
     Boolean(existingSession) && !hasChatContent(existingSession) && hasContent;
   const nextRecord: ChatSessionRecord = {
@@ -269,7 +283,7 @@ export const saveActiveChatState = async (
     createdAt: shouldAnchorCreatedAtToFirstMessage
       ? now
       : existingSession?.createdAt ?? now,
-    updatedAt: now,
+    updatedAt: hasContentChanged ? now : existingSession?.updatedAt ?? now,
     sessionId: state.sessionId,
     messages: sanitizeMessages(state.messages),
     branchGroups: sanitizeBranchGroups(state.branchGroups),
@@ -315,7 +329,6 @@ export const updateChatSessionTitle = async (
     title: normalizedTitle,
     isTitleManuallyEdited:
       options?.isTitleManuallyEdited ?? session.isTitleManuallyEdited ?? false,
-    updatedAt: Date.now(),
   });
 };