New internal/version package: ldflags-stamped Commit with a
debug.ReadBuildInfo VCS fallback for host builds. Startup log line
carries commit + Go version; --version prints the hash and exits.
Makefile computes GIT_COMMIT (12 chars, -dirty on any local change) and
passes it to docker-build/buildx; Dockerfile injects it via -ldflags and
an org.opencontainers.image.revision label. make build now uses ./cmd —
file-argument builds skip Go's automatic VCS stamp.
Co-Authored-By: Claude <noreply@anthropic.com>
