fix(system): 修正超级管理员标识及关联查询逻辑

- 将 TenantMapper.xml 中用户表连接更新为使用 gxwebsoft_core.sys_user
- 修改关联查询条件，使用 is_super_admin 替代 is_admin 标识
- 调整 User 实体中 isSuperAdmin 字段，移除@TableField注解以确保正确映射

src/main/java/com/gxwebsoft/common/system/entity/User.java

@@ -197,7 +197,6 @@ public class User implements UserDetails {
     private Integer isOrganizationAdmin;
 
     @Schema(description = "是否超级管理员")
-    @TableField(exist = false)
     private Boolean isSuperAdmin;
 
     @Schema(description = "租户管理员ID")

src/main/java/com/gxwebsoft/common/system/mapper/xml/TenantMapper.xml

@@ -8,11 +8,7 @@
                u.phone,u.username
         FROM sys_tenant a
         LEFT JOIN sys_company b ON a.tenant_id = b.tenant_id
-        LEFT JOIN sys_user u ON u.tenant_id = a.tenant_id AND u.is_admin = 1
+        LEFT JOIN gxwebsoft_core.sys_user u ON u.tenant_id = a.tenant_id AND u.is_super_admin = 1 AND u.deleted = 0
-            AND u.user_id = (
-                SELECT MIN(user_id) FROM sys_user
-                WHERE tenant_id = a.tenant_id AND is_admin = 1 AND deleted = 0
-            )
         <where>
             <if test="param.tenantId != null">
                 AND a.tenant_id = #{param.tenantId}