Canonical S3 SDK across the stack is the Hanzo S3 fork at
github.com/hanzos3/go-sdk (package `s3`). Imports use an explicit
`s3 "github.com/hanzos3/go-sdk"` alias to avoid the `go-sdk` last-path-
segment mismatch with `package s3`.
`pkg/backup/s3.go` swept: `minio.Client` → `s3.Client`, `minio.New` →
`s3.New`, `minio.Options` → `s3.Options`, `minio.MakeBucketOptions` →
`s3.MakeBucketOptions`, `minio.PutObjectOptions` → `s3.PutObjectOptions`.
Field name `s3Client *s3.Client` is fine (no shadow with the package
qualifier).
Dropped stale `luxfi/zapdb v1.0.0` entries in go.work.sum that were
blocking go mod tidy (their hashes no longer match the proxy after
zapdb's own sweep).
No behavioral changes.