[Feature] Support S3-compatible object storage (S3/MinIO) filesystem

[Pandas886]

Description

Add support for S3-compatible object storage as a filesystem backend in paimon-cpp, including:

• AWS S3 — native S3 access
• MinIO — S3-compatible self-hosted object storage
• Other S3-compatible services (e.g. Alibaba OSS, Ceph RGW, etc.)

Motivation

Many data lakehouse deployments use object storage (S3, MinIO, OSS) as the underlying storage layer. Currently paimon-cpp appears to support only local filesystem, with HDFS support also in progress (#33). S3/MinIO support would significantly broaden the adoption scenarios for paimon-cpp, especially:

1. Cloud-native deployments on AWS / Alibaba Cloud / other cloud providers
2. On-premise environments using MinIO as the storage backend
3. Hybrid setups where data lives on object storage

Possible Implementation

• Implement a S3FileSystem class conforming to the existing FileSystem interface
• Use the AWS C++ SDK (aws-sdk-cpp) with S3 module, or a lightweight alternative like aws-c-s3
• Support configurable endpoint, region, access key, secret key, and path-style access (for MinIO compatibility)
• The Java version of Paimon already has S3 filesystem support, which can serve as a reference

Additional Context

Related: #33 (HDFS filesystem support) — once the filesystem abstraction is mature, adding new backends like S3 should be straightforward.

[lxy-9602]

Hi @Pandas886, thanks for raising this issue, and sorry for the delayed response.

For Aliyun OSS related scenarios, paimon-cpp currently supports access through Jindo. However, native support for S3-compatible filesystem backends such as AWS S3 and MinIO would still be valuable for broader object storage deployments.

Would you be interested in helping implement an S3 filesystem backend and contributing it to the community? We would be happy to discuss the design and review the contribution.