fix(user): 修复默认角色创建时租户不存在校验问题

- 增加根据邮箱查询账号的方法，忽略租户隔离
- 引入 TenantService 以校验租户是否存在
- 在创建默认“用户”角色时添加租户存在性校验
- 防止因租户缺失导致外键约束失败异常

src/main/java/com/gxwebsoft/common/system/mapper/UserMapper.java

@@ -81,6 +81,15 @@ public interface UserMapper extends BaseMapper<User> {
     @InterceptorIgnore(tenantLine = "true")
     List<User> selectAccountsByPhone(@Param("phone") String phone);
 
+    /**
+     * 根据邮箱查询所有账号（忽略租户隔离）
+     *
+     * @param email 邮箱
+     * @return List<User>
+     */
+    @InterceptorIgnore(tenantLine = "true")
+    List<User> selectAccountsByEmail(@Param("email") String email);
+
     /**
      * 根据手机号统计账号数量（忽略租户隔离）
      *

src/main/java/com/gxwebsoft/common/system/service/impl/UserServiceImpl.java

@@ -54,6 +54,8 @@ public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements Us
     private OrganizationService organizationService;
     @Resource
     private UserRefereeService userRefereeService;
+    @Resource
+    private TenantService tenantService;
 
     @Autowired(required = false)
     private SyncMessageProducer syncMessageProducer;
@@ -346,6 +348,10 @@ public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements Us
             role = roleService.getOne(roleQw, false);
             // If the default "user" role is missing (fresh DB / incomplete init), create it to avoid empty roles.
             if (role == null && addUser.getTenantId() != null && "user".equals(roleCode)) {
+                // 校验租户是否存在，否则插入 sys_role 会因外键约束失败（tenant_id 引用 sys_tenant）
+                if (tenantService.getById(addUser.getTenantId()) == null) {
+                    throw new BusinessException("租户不存在(tenantId=" + addUser.getTenantId() + ")，无法创建默认角色");
+                }
                 Role defaultRole = new Role();
                 defaultRole.setRoleName("注册用户");
                 defaultRole.setRoleCode("user");