Add cluster multipart uploads and listings

README.md

@@ -43,10 +43,10 @@ New objects retain their content type and key. Objects written by the earlier si
 - ✅ `PutObject`, `GetObject`, `HeadObject`, and `DeleteObject` in both modes
 - ✅ Single-range GET and `ListObjectsV2` in both modes
 - ✅ SHA-256 payload verification and `x-amz-checksum-sha256` in both modes
-- ✅ `CreateMultipartUpload`, `UploadPart`, `CompleteMultipartUpload`, and `AbortMultipartUpload` in single-node mode
-- ⬜ Multipart uploads in cluster mode
+- ✅ `CreateMultipartUpload`, `UploadPart`, `CompleteMultipartUpload`, and `AbortMultipartUpload` in both modes
+- ✅ `ListParts` and `ListMultipartUploads` in both modes
 - ⬜ Presigned URLs and streaming Signature V4 uploads
-- ⬜ `CopyObject`, `ListParts`, and `ListMultipartUploads`
+- ⬜ `CopyObject`
 - ⬜ `Content-MD5` and checksum algorithms other than SHA-256
 - ⬜ Bucket creation and listing, object versioning, ACLs, tags, and user metadata
 
@@ -92,6 +92,8 @@ docker compose --env-file /path/to/cluster.env -f compose.cluster.yaml run --rm
 
 The cluster S3 endpoint binds to `127.0.0.1:9001`; storage nodes and PostgreSQL have no published ports. The separate repair container holds the repair credential and restores missing or corrupt replicas.
 
+Multipart parts are stored on cluster nodes and indexed in PostgreSQL. Incomplete uploads count toward the logical capacity limit; abort them to release that capacity. Repair includes staged parts. The gateway upgrades the metadata schema when it starts, so back up the database before upgrading an existing cluster.
+
 Node UUIDs persist on their volumes, and replica manifests use those UUIDs so reordering configured URLs cannot move an existing replica. Each node also has an operator-assigned physical host UUID. New writes require acknowledgements from two different host UUIDs. The optional `CLUSTER_TEST_NODE_DOMAINS=true` override counts containers instead, solely for local process tests; all containers in this Compose file share one physical host.
 
 ## Migrating a local cluster