feat(multipart): list and abort incomplete uploads

[cxymds]

Summary

• implement ls --incomplete for bucket/prefix listings with complete key/upload-marker pagination
• implement exact and explicitly recursive rm --incomplete, including dry-run and idempotent NoSuchUpload handling
• add typed core/S3 multipart APIs, deterministic output-v3/table/quiet results, per-item partial failures, cancellation, bounded concurrency, and bounded retries
• detect stalled/cyclic pagination before unsafe cleanup

Validation

• 13 end-to-end multipart command tests covering empty, multi-page, prefix, recursive, dry-run, output modes, access denial, abort, and retry
• unit tests for retry, concurrency, partial results, interruption, and exit codes
• cargo fmt --all --check
• cargo clippy --workspace -- -D warnings
• cargo test --workspace
• git diff --check

Dependency

Requires rustfs/rustfs#5195 for correct RustFS bucket/prefix multipart enumeration.

Closes rustfs/backlog#1366
Refs rustfs/backlog#1405

BREAKING: no