feat: 添加员工门户项目及相关后端改造

- 新增 hzhub-portal-employee 员工门户前端项目（基于 Vue3 + Element Plus）
- 后端登录接口增加返回 nickName 字段
- 移除 KnowledgeInfoController 的 @SaCheckPermission 注解
- 删除 hzhub-portal-company 旧门户项目
- 更新项目文档和架构说明
- 添加后台运行管理脚本（start-all.sh / status-all.sh / stop-all.sh）
- 更新 docker-compose 配置

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

hzhub-portal-employee/license

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 hzhub
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.