cacher v0.1.0 — first public release Replaces the s3_cache_or_curl / s3_cache_docker_image shell helpers in tarantool-protobuf/.builds/lib/ci-lib.sh with a single static Go binary. Highlights: - init/doctor: persist config, smoke-test S3 credentials. - File caching: download/upload/exists/list/delete, with URL fallback and --sha256 verification. - Docker images: streamed save | zstd → S3 multipart upload, and inverse (no on-disk tempfile, pure-Go zstd). - Directory caching: tar+zstd of resolved trees keyed by lockfile hash — closes the gap left by the shell version. - --hash-from <path> (repeatable) matches sha256sum | cut -c1-N byte-for-byte, so existing keys migrate without recomputation. - Garage-compatible defaults; verified end-to-end against dxflrs/garage:v2.3.0 via testcontainers-go. See CHANGELOG.md for the full surface and the Fixed/Added sections.