v0.4.0

[0.4.0]

Added

• wfs.RenameFS support via S3 CopyObject + DeleteObject (#8).
• wfs.SyncWriterFile support (no-op — S3 writes atomically on Close) (#8).
• S3API interface defined in this package for testability (#7).
• Builder methods: WithClient, WithConfig, WithContext (#7).
• NewWithClient convenience constructor (#7).
• Lazy client initialization — New(bucket) defers AWS config loading
  until the first operation (#7).
• CI: GitHub Actions with Go version matrix (1.24, stable),
  golangci-lint, govulncheck.
• Dependabot for weekly Go module and GitHub Actions updates.
• CHANGELOG.md (#9).

Changed

• Breaking: Migrated from aws-sdk-go (v1) to aws-sdk-go-v2 (#7).
• Breaking: New(bucket) no longer takes context.Context or
  returns error. Use WithContext to set a context (#7).
• Breaking: NewWithSession removed. Use NewWithClient or
  New(bucket).WithConfig(cfg) (#7).
• Breaking: NewWithAPI renamed to NewWithClient. The parameter
  type changed from s3iface.S3API to the S3API interface defined in
  this package (#7).
• Upgraded wfs dependency from v0.4.0 to v0.5.0.
• Removed io2 dependency (replaced with internal lazyReadCloser).
• Minimum Go version set to 1.24.