feat: 增加附件表结构与本地上传接口

src/main/java/com/bruce/common/service/ISysAttachmentService.java

@@ -0,0 +1,10 @@
+package com.bruce.common.service;
+
+import com.baomidou.mybatisplus.extension.service.IService;
+import com.bruce.common.entity.SysAttachment;
+import org.springframework.web.multipart.MultipartFile;
+
+public interface ISysAttachmentService extends IService<SysAttachment> {
+
+    SysAttachment upload(MultipartFile file, String sourceType, Long sourceId);
+}