fix(realname): 增加身份证唯一性校验，防止同一证件重复实名

backend/internal/modules/adminuser/handler.go

@@ -246,6 +246,8 @@ func writeAdminUserError(c *gin.Context, err error) {
 		response.BadRequest(c, "姓名或身份证号格式不正确")
 	case errors.Is(err, ErrRealnameAlreadyVerified):
 		response.Error(c, http.StatusConflict, "realname_already_verified", "该用户已完成实名认证，如需修改请先撤销实名")
+	case errors.Is(err, ErrRealnameIDNoUsed):
+		response.Error(c, http.StatusConflict, "realname_id_no_used", "该身份证号已绑定其他实名账号，不能重复认证")
 	case errors.Is(err, ErrRealnameNotRevocable):
 		response.Error(c, http.StatusConflict, "realname_not_revocable", "该用户当前没有可撤销的实名信息")
 	case errors.Is(err, ErrInvalidWalletDirection):