feat(tenant): 添加租户删除时的数据清理逻辑

- 在SysDictItem和SysDictType实体中添加isDeleted字段用于逻辑删除
- 注入DeviceMapper用于处理设备数据删除
- 实现完整的租户删除逻辑，包括角色、组织、用户关联的逻辑删除
- 添加用户清理机制，删除不再属于任何租户的孤立用户
- 实

backend/src/main/java/com/imeeting/entity/SysDictItem.java

@@ -21,4 +21,6 @@ public class SysDictItem extends BaseEntity {
 
   @TableField(exist = false)
   private Long tenantId;
+  @TableField(exist = false)
+  private Integer isDeleted;
 }

backend/src/main/java/com/imeeting/entity/SysDictType.java

@@ -19,4 +19,6 @@ public class SysDictType extends BaseEntity {
 
   @TableField(exist = false)
   private Long tenantId;
+  @TableField(exist = false)
+  private Integer isDeleted;
 }

backend/src/main/java/com/imeeting/service/impl/SysTenantServiceImpl.java

@@ -29,12 +29,14 @@ public class SysTenantServiceImpl extends ServiceImpl<SysTenantMapper, SysTenant
     private final SysRolePermissionMapper sysRolePermissionMapper;
     private final SysTenantUserService sysTenantUserService;
     private final PasswordEncoder passwordEncoder;
+    private final com.imeeting.mapper.DeviceMapper deviceMapper;
 
     public SysTenantServiceImpl(SysUserService sysUserService, SysRoleService sysRoleService,
                                 SysOrgService sysOrgService, SysPermissionService sysPermissionService,
                                 SysParamService sysParamService, SysUserRoleMapper sysUserRoleMapper,
                                 SysRolePermissionMapper sysRolePermissionMapper,
-                                SysTenantUserService sysTenantUserService, PasswordEncoder passwordEncoder) {
+                                SysTenantUserService sysTenantUserService, PasswordEncoder passwordEncoder,
+                                com.imeeting.mapper.DeviceMapper deviceMapper) {
         this.sysUserService = sysUserService;
         this.sysRoleService = sysRoleService;
         this.sysOrgService = sysOrgService;
@@ -44,6 +46,57 @@ public class SysTenantServiceImpl extends ServiceImpl<SysTenantMapper, SysTenant
         this.sysRolePermissionMapper = sysRolePermissionMapper;
         this.sysTenantUserService = sysTenantUserService;
         this.passwordEncoder = passwordEncoder;
+        this.deviceMapper = deviceMapper;
+    }
+
+    @Override
+    @Transactional(rollbackFor = Exception.class)
+    public boolean removeById(java.io.Serializable id) {
+        Long tenantId = (Long) id;
+        
+        // 1. 获取该租户下的所有用户 ID
+        List<SysTenantUser> tenantUsers = sysTenantUserService.list(
+            new LambdaQueryWrapper<SysTenantUser>().eq(SysTenantUser::getTenantId, tenantId)
+        );
+        List<Long> userIds = tenantUsers.stream().map(SysTenantUser::getUserId).collect(Collectors.toList());
+
+        // 2. 逻辑删除租户下的角色
+        sysRoleService.lambdaUpdate()
+            .set(SysRole::getIsDeleted, 1)
+            .eq(SysRole::getTenantId, tenantId)
+            .update();
+            
+        // 3. 逻辑删除租户下的组织
+        sysOrgService.lambdaUpdate()
+            .set(SysOrg::getIsDeleted, 1)
+            .eq(SysOrg::getTenantId, tenantId)
+            .update();
+            
+        // 4. 逻辑删除用户与租户的关联
+        sysTenantUserService.remove(new LambdaQueryWrapper<SysTenantUser>().eq(SysTenantUser::getTenantId, tenantId));
+
+        // 5. 逻辑删除用户与角色的关联 (带租户隔离的)
+        sysUserRoleMapper.delete(new com.baomidou.mybatisplus.core.conditions.query.QueryWrapper<SysUserRole>().eq("tenant_id", tenantId));
+        
+        // 6. 清理孤立用户：如果用户不再属于任何租户，则逻辑删除该用户
+        if (userIds != null && !userIds.isEmpty()) {
+            for (Long userId : userIds) {
+                long count = sysTenantUserService.count(
+                    new LambdaQueryWrapper<SysTenantUser>().eq(SysTenantUser::getUserId, userId)
+                );
+                if (count == 0) {
+                    sysUserService.removeById(userId);
+                }
+            }
+        }
+
+        // 7. 逻辑删除租户下的设备
+        if (deviceMapper != null) {
+            deviceMapper.delete(new com.baomidou.mybatisplus.core.conditions.query.QueryWrapper<com.imeeting.entity.Device>().eq("tenant_id", tenantId));
+        }
+
+        // 8. 最后逻辑删除租户记录本身
+        return super.removeById(id);
     }
 
     @Override