fix(oss): 修复MinIO SDK配置避免region空指针异常

- 调整MinIO客户端配置，使用 OSSClientBuilder 的链式调用构建
- 明确指定region为"us-east-1"，防止自定义域名推导region失败导致NPE
- 保持SignatureVersion为V4，启用从endpoint提取配置信息以支持path-style访问
- 统一AliOssController和FileRecordServiceImpl中的MinIO配置逻辑

src/main/java/com/gxwebsoft/common/system/controller/AliOssController.java

@@ -121,11 +121,16 @@ public class AliOssController extends BaseController {
     OSS ossClient;
     if ("minio".equals(uploadMethod)) {
       ClientBuilderConfiguration minioConfig = new ClientBuilderConfiguration();
-      // 3.17 已移除 setPathStyleAccess；用 setExtractSettingFromEndpoint 让 SDK 对 MinIO 这类
-      // 非阿里云 endpoint 自动按 path-style 访问，并从 endpoint 推导 region
+      // MinIO 兼容 S3：V4 签名 + path-style。自定义域名无法从 endpoint 推导 region，
+      // 必须显式指定（MinIO 默认 us-east-1），否则 OSSV4Signer.getRegion() 为 null 触发 NPE。
       minioConfig.setSignatureVersion(SignVersion.V4);
       minioConfig.setExtractSettingFromEndpoint(true);
-      ossClient = new OSSClientBuilder().build(endpoint, credentialsProvider, minioConfig);
+      ossClient = OSSClientBuilder.create()
+          .endpoint(endpoint)
+          .credentialsProvider(credentialsProvider)
+          .clientConfiguration(minioConfig)
+          .region("us-east-1")
+          .build();
     } else {
       ossClient = new OSSClientBuilder().build(endpoint, credentialsProvider);
     }

src/main/java/com/gxwebsoft/common/system/service/impl/FileRecordServiceImpl.java

@@ -101,11 +101,16 @@ public class FileRecordServiceImpl extends ServiceImpl<FileRecordMapper, FileRec
     OSS ossClient;
     if ("minio".equals(uploadMethod)) {
       ClientBuilderConfiguration minioConfig = new ClientBuilderConfiguration();
-      // 3.17 已移除 setPathStyleAccess；用 setExtractSettingFromEndpoint 让 SDK 对 MinIO 这类
-      // 非阿里云 endpoint 自动按 path-style 访问，并从 endpoint 推导 region
+      // MinIO 兼容 S3：V4 签名 + path-style。自定义域名无法从 endpoint 推导 region，
+      // 必须显式指定（MinIO 默认 us-east-1），否则 OSSV4Signer.getRegion() 为 null 触发 NPE。
       minioConfig.setSignatureVersion(SignVersion.V4);
       minioConfig.setExtractSettingFromEndpoint(true);
-      ossClient = new OSSClientBuilder().build(endpoint, credentialsProvider, minioConfig);
+      ossClient = OSSClientBuilder.create()
+          .endpoint(endpoint)
+          .credentialsProvider(credentialsProvider)
+          .clientConfiguration(minioConfig)
+          .region("us-east-1")
+          .build();
     } else {
       ossClient = new OSSClientBuilder().build(endpoint, credentialsProvider);
     }