fix(chat): preserve private send response fields

src/data/dto/chat/chat_send_response.ts

@@ -26,6 +26,9 @@ export class ChatSendResponse {
   declare readonly paywallTriggered: boolean;
   declare readonly showUpgrade: boolean;
   declare readonly imageType: string | null;
+  declare readonly isPrivate: boolean | null;
+  declare readonly privateLocked: boolean | null;
+  declare readonly privateHint: string | null;
   declare readonly imageUrl: string | null;
 
   private constructor(input: ChatSendResponseInput) {

src/data/schemas/chat/chat_send_response.ts

@@ -30,6 +30,9 @@ export const ChatSendResponseSchema = z.object({
   paywallTriggered: z.boolean().default(false),
   showUpgrade: z.boolean().default(false),
   imageType: z.string().nullable().default(null),
+  isPrivate: z.boolean().nullable().default(null),
+  privateLocked: z.boolean().nullable().default(null),
+  privateHint: z.string().nullable().default(null),
   imageUrl: z.string().nullable().default(null),
 });