refactor(chat): wire sendMessageHttpActor for HTTP message sending and update response handling

src/stores/chat/chat-machine.helpers.ts

@@ -19,6 +19,8 @@ import { chatRepository } from "@/data/repositories/chat_repository";
 import type { IChatRepository } from "@/data/repositories/interfaces";
 import { ChatStorage } from "@/data/storage/chat/chat_storage";
 import { AuthStorage } from "@/data/storage/auth/auth_storage";
+import { ChatSendResponse } from "@/data/dto/chat/chat_send_response";
+import { formatDate } from "@/utils/date";
 import { Result } from "@/utils/result";
 
 // ============================================================// Constants
@@ -52,6 +54,19 @@ export function localMessagesToUi(
   }));
 }
 
+/**
+ * ChatSendResponse → UiMessage（**纯函数**）
+ * - 业务事实：后端响应**就是** AI 的回复
+ * - 用后端 `timestamp`（**不**用本地 time）—— 多设备/时区**一致**
+ */
+export function sendResponseToUiMessage(response: ChatSendResponse): UiMessage {
+  return {
+    content: response.reply,
+    isFromAI: true,
+    date: formatDate(new Date(response.timestamp)),
+  };
+}
+
 // ============================================================// Result → number 映射
 // ============================================================
 /** 日配额 Result → number（**纯函数**） */