refactor: simplify chat fork flow

src/components/chat/chatStorage.ts

@@ -2,12 +2,11 @@ import { apiFetch } from "@/lib/apiFetch";
 import { config } from "@config/config";
 
 import type {
-  BranchGroup,
   ChatSessionSummary,
   LoadedChatState,
   Message,
 } from "./GlobalChatbox.types";
-import { cloneBranchGroups, cloneMessages } from "./GlobalChatbox.utils";
+import { cloneMessages } from "./GlobalChatbox.utils";
 
 type BackendSessionPayload = {
   id?: string;
@@ -23,22 +22,16 @@ export const createEmptyChatState = (): LoadedChatState => ({
   isTitleManuallyEdited: false,
   messages: [],
   sessionId: undefined,
-  branchGroups: [],
 });
 
 const sanitizeMessages = (messages: Message[] | undefined) =>
   Array.isArray(messages) ? cloneMessages(messages) : [];
 
-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 = (
@@ -107,7 +100,6 @@ const fetchBackendChatSession = async (sessionId: string): Promise<LoadedChatSta
     is_title_manually_edited?: boolean;
     session_id?: string;
     messages?: Message[];
-    branch_groups?: BranchGroup[];
     is_streaming?: boolean;
     run_status?: string;
   };
@@ -116,7 +108,6 @@ const fetchBackendChatSession = async (sessionId: string): Promise<LoadedChatSta
     isTitleManuallyEdited: payload.is_title_manually_edited ?? false,
     messages: sanitizeMessages(payload.messages),
     sessionId: payload.session_id ?? payload.id,
-    branchGroups: sanitizeBranchGroups(payload.branch_groups),
     isStreaming: payload.is_streaming ?? false,
     runStatus: payload.run_status,
   };
@@ -167,7 +158,6 @@ const saveBackendChatState = async (
         title: normalizeTitle(state.title),
         is_title_manually_edited: state.isTitleManuallyEdited ?? false,
         messages: sanitizeMessages(state.messages),
-        branch_groups: sanitizeBranchGroups(state.branchGroups),
       }),
       projectHeaderMode: "include",
       userHeaderMode: "include",