fix: 修复 MinIO 上传文件时 ContentType 可能根据平台不同导致为空问题

basic-common/minio/src/main/java/com/yiring/common/core/Minio.java

@@ -12,8 +12,10 @@ import java.nio.file.Path;
 import java.time.LocalDateTime;
 import java.time.format.DateTimeFormatter;
 import java.util.Objects;
+import java.util.Optional;
 import lombok.Cleanup;
 import lombok.NonNull;
+import org.springframework.http.MediaType;
 import org.springframework.stereotype.Component;
 import org.springframework.web.multipart.MultipartFile;
 
@@ -88,7 +90,7 @@ public record Minio(MinioConfig config, MinioClient client) {
             .bucket(config.getBucket())
             .stream(is, -1, PutObjectArgs.MIN_MULTIPART_SIZE)
             .object(object)
-            .contentType(contentType)
+            .contentType(Optional.ofNullable(contentType).orElse(MediaType.APPLICATION_OCTET_STREAM_VALUE))
             .build();
         return client.putObject(args);
     }