Use Docker's TARGETARCH variable to download the correct architecture
binaries for Go and Hugo during multi-platform builds. This fixes the
build failure for linux/arm64 where amd64 binaries were being downloaded.
- Add ARG TARGETARCH to capture target architecture
- Replace hardcoded linux-amd64 with linux-${TARGETARCH}
- Applies to both Go and Hugo downloads
- Backwards compatible with local single-platform builds
- Add multi-stage Dockerfile with pinned tool versions (Node 24.10.0, Go 1.25.1, Hugo 0.151.0)
- Create .env.versions as single source of truth for all tool versions
- Add GitHub Actions CI workflow for automated OCI image builds
- Multi-arch support (amd64, arm64)
- Automatic version loading from .env.versions
- Docker registry push with metadata tags
- Add Taskfile tasks for local OCI image building and testing
- task build:oci-image - Build with version-pinned dependencies
- task test:oci-image - Build and test container locally
- Pin devbox.json to specific versions matching .env.versions
- Add comprehensive documentation (DOCKER.md, VERSIONS.md)
- Add helper script (scripts/get-versions.sh) for version extraction
This enables consistent development and production environments with
identical tool versions across local devbox, Docker builds, and CI/CD.
