claudebox v2.1.2 — bump baked-in toolchains and harden the image supply chain Toolchains: claude-code 2.1.197 -> 2.1.220, Go 1.26.1 -> 1.26.5, kubectl apt channel v1.31 -> v1.36, pyenv Python 3.12.11 -> 3.12.13. Supply chain: pin the aicodebox base image by @sha256 digest, and SHA256-verify the Go tarball (per-arch) before extraction instead of piping curl into tar.