feat(ai-companion): 新增AI角色举报功能

- 新增举报接口 POST /ai-companion/report，支持多选举报类型
- 引入 KeyboardAiCompanionReportService 处理举报业务
- 补充举报相关错误码：类型无效、角色ID为空、类型为空
- 新增实体、DTO、Mapper、Service 及 XML 配置，完成举报数据持久化

src/main/java/com/yolo/keyborad/mapper/KeyboardAiCompanionReportMapper.java

@@ -0,0 +1,12 @@
+package com.yolo.keyborad.mapper;
+
+import com.baomidou.mybatisplus.core.mapper.BaseMapper;
+import com.yolo.keyborad.model.entity.KeyboardAiCompanionReport;
+
+/*
+* @author: ziin
+* @date: 2026/1/29 16:17
+*/
+    
+public interface KeyboardAiCompanionReportMapper extends BaseMapper<KeyboardAiCompanionReport> {
+}