V3 deterministic Brotli compression capability pack. By-value connector composition (service_kind=cli, no separate ingredient): one local brotli CLI ingredient exposes readiness, best/default compression, fast compression, decompression, and compressed-stream integrity testing. Fixed-function and reproducible: the executor materializes source files and owns the throwaway output directory, while brotli writes fixed output files that are captured as result.file_ref. Write-tier operations write only to an engine-managed output dir, read-tier testing returns only exit status, and recipes cannot pass arbitrary flags, dictionaries, comments, large-window modes, source-removal flags, shell wrappers, or caller-controlled output paths. Requires the brotli binary on PATH (Debian/Ubuntu: apt install brotli; macOS: brew install brotli). Local and no-egress.