feat(dept): 创建部门管理后端业务层与路由

ISysDeptService + SysDeptService: CRUD + 子部门删除校验 + 审计日志；
DeptCreateRequest/DeptUpdateRequest: 验证注解与前端 VALIDATION 对齐；
SysDeptHandler: RESTful API (GET/POST/PUT/DELETE /api/depts)；
SystemRouter: 注册部门路由。

novalon-manage-api/manage-app/src/main/java/cn/novalon/manage/app/config/SystemRouter.java

@@ -7,6 +7,7 @@ import cn.novalon.manage.sys.handler.dictionary.DictionaryHandler;
 import cn.novalon.manage.sys.handler.dict.SysDictHandler;
 import cn.novalon.manage.sys.handler.log.SysLogHandler;
 import cn.novalon.manage.sys.handler.log.OperationLogHandler;
+import cn.novalon.manage.sys.handler.dept.SysDeptHandler;
 import cn.novalon.manage.sys.handler.menu.MenuHandler;
 import cn.novalon.manage.sys.handler.role.SysRoleHandler;
 import cn.novalon.manage.sys.handler.permission.SysPermissionHandler;
@@ -51,7 +52,8 @@ public class SystemRouter {
             SysUserMessageHandler messageHandler,
             SysFileHandler fileHandler,
             SysPermissionHandler permissionHandler,
-            PasswordDiagnosticHandler passwordDiagnosticHandler) {
+            PasswordDiagnosticHandler passwordDiagnosticHandler,
+            SysDeptHandler deptHandler) {
         
         return route()
                 // ========== 诊断路由 ==========
@@ -115,6 +117,13 @@ public class SystemRouter {
                 .PUT("/api/config/{id}", configHandler::updateConfig)
                 .DELETE("/api/config/{id}", configHandler::deleteConfig)
                 
+                // ========== 部门路由 ==========
+                .GET("/api/depts", deptHandler::getAllDepts)
+                .GET("/api/depts/{id}", deptHandler::getDeptById)
+                .POST("/api/depts", deptHandler::createDept)
+                .PUT("/api/depts/{id}", deptHandler::updateDept)
+                .DELETE("/api/depts/{id}", deptHandler::deleteDept)
+                
                 // ========== 日志路由 ==========
                 .GET("/api/logs/login", logHandler::getAllLoginLogs)
                 .GET("/api/logs/login/page", logHandler::getLoginLogsByPage)