SpinelKit consolidates the pure-Ruby shims that every Spinel-compiled project would otherwise hand-roll and that Spinel (the Ruby->native AOT compiler) does not provide: .git/HEAD provenance, URL percent-codec + query parsing, a minimal levelled logger, and a hex digit/byte codec. (JSON left in 0.3.0: Spinel now bundles `json` as a require-gated stdlib package, so consumers use JSON.parse/JSON.generate directly.) Pure Ruby, no native extension, no runtime dependencies -- it vendors cleanly via bundler-spinel. Pre-alpha.