Related issue

• Closes rustfs/backlog#1406.
• Parent roadmap: rustfs/backlog#1361.

Background and user impact

rc mb advertised --region, --with-versioning, and --with-lock but rejected them at runtime. RustFS supports a region-bearing CreateBucket request, creation-time Object Lock, bucket versioning, and the read APIs needed to verify effective state.

Object Lock cannot be enabled retroactively. RustFS also reports a service-level bucket location, so the CLI must report observed state without claiming a per-bucket region that the server did not persist.

Solution

• Add typed CreateBucketOptions with a safe option-free default.
• Normalize --with-lock to effective versioning and validate option invariants before network access.
• Send region configuration only when explicitly requested and the Object Lock header only during creation.
• Enable versioning after creation for non-lock versioning requests.
• Verify effective versioning, Object Lock, and service-reported location.
• Reconcile -p safely for existing buckets without pretending Object Lock can be enabled later.
• Preserve completed and failed stages; never delete a successfully created bucket as rollback.
• Add output-v3 bucket_operations success, empty, partial, and error contracts.
• Preserve all current versioning, Object Lock, mirror, transfer, watch, ops, and replication behavior.

Validation

• cargo fmt --all --check
• cargo clippy --workspace -- -D warnings
• cargo test --workspace
• Focused CreateBucket, mb, output-v3, help, Object Lock, versioning, and mirror-planner tests
• Conflict-marker and staged/unstaged diff checks

All checks pass with zero failures. Focused results include mb 16/16 in both lib and bin, output-v3 12/12, Object Lock 17/17, versioned objects 10/10, and mirror planner 5/5.

BREAKING process

BREAKING: this updates the protected rc command-reference contract and migrates legacy mb JSON to the output-v3 bucket_operations envelope. Output v1 and v2, exit-code definitions, and local configuration schemas are unchanged.