refactor(chat): remove guest history synchronization

src/data/services/api/chat_api.ts

@@ -11,7 +11,6 @@ import {
   ChatPreviewsResponseSchema,
   ChatSendResponse,
   ChatSendResponseSchema,
-  ChatSyncRequest,
   SendMessageRequest,
   UnlockHistoryRequest,
   UnlockHistoryResponse,
@@ -67,17 +66,6 @@ export class ChatApi {
     return ChatPreviewsResponseSchema.parse(unwrap(env));
   }
 
-  async syncGuestHistory(
-    body: ChatSyncRequest,
-    options?: { signal?: AbortSignal },
-  ): Promise<void> {
-    await httpClient<ApiEnvelope<unknown>>(ApiPath.chatSync, {
-      method: "POST",
-      body,
-      ...(options?.signal ? { signal: options.signal } : {}),
-    }).then(unwrap);
-  }
-
   /**
    * 解锁单条历史付费 / 私密消息
    */