fix: 处理null问题

buhuazhen

2026-06-01 facbfd2b1a0eb1ea971b699def8c85a43c5fa7fa

 src/main/java/com/ruoyi/basic/dto/CustomerDto.java

@@ -21,4 +21,8 @@

    private List<CustomerFollowUpDto> followUpList;

    private String usageUserName;

    private String togetherUserNames;

}