feat: add core entities, controllers, services, and mappers across multi-module project

admin/src/main/java/cn/unizk/service/ComboService.java

@@ -0,0 +1,7 @@
+package cn.unizk.service;
+
+import cn.unizk.entity.po.Combo;
+import com.baomidou.mybatisplus.extension.service.IService;
+
+public interface ComboService extends IService<Combo> {
+}