[tiptenbrink]

Ready for review. CI passes, with the borink adapter pinned at object-storage a231d3b, which passes every case.

Summary

• Copy semantics a client decides from the documentation, 15 cases:
  • An S3 REPLACE replaces the content properties with the metadata, so a copy naming only metadata gets binary/octet-stream.
  • REPLACE with no metadata or no tags clears them. A client API that cannot say so may refuse or decline.
  • UploadPartCopy reports a failed source condition as 412 PreconditionFailed.
  • Copy Blob ignores content properties, while Put Blob From URL honors them.
  • A From URL source that is missing is 404 CannotVerifyCopySource.
• Tags of a version or snapshot, 12 cases. Azure sets a snapshot's tags, though its reference names only versionid. S3 answers a deleted version with 404 NoSuchVersion and an ID it could never have given with 400 InvalidArgument.
• A version or snapshot per key in a batch delete, 7 cases. A delete_many key may be {"key", "version"}, on Azure also {"key", "snapshot"}. blob_batch now compares each subrequest's query.
• S3 version listings, 8 cases. list_page with include: ["versions"] pages by continuation_token and a new version_marker. A directory bucket answers 501 NotImplemented, which a client may refuse.
• Restoring from archive, 14 cases. A new restore call reports state started or readable, and reads report restore_status.
• Every case is verified live. REFERENCE.md has the new result fields.
• The AWS C++ SDK sends ?tagging=tagging, ?restore=restore and ?versions=versions beside another parameter. S3 accepts that, so the cases do too.

Test plan

• object-tests validate cases/operations.json passes (1,132 cases).
• cargo test passes.