Wraps /etc/pi-devbox/build-manifest.json (already written at docker-build
time in Dockerfile.variant) into a human-readable summary instead of
requiring users to know the manifest path and pipe it through jq
themselves.
- rootfs/usr/local/bin/pi-devbox-version: human (default) / --json /
--quiet output modes. Also flags live drift — compares the baked
pi_version against the actually-running `pi --version` and warns
on mismatch rather than trusting the manifest blindly (same
ground-truth philosophy as the manifest generation itself). Exits 1
with a short stderr notice on images built before the manifest
existed, instead of failing silently.
- entrypoint-user.sh: calls it as the very first line. CMD is
`bash -l` with tty:true in compose, so this banner lands directly
above the first prompt on container start — no separate motd/bashrc
hook needed (deliberately not wired into .bash_aliases, which would
reprint on every docker exec -it).
- Dockerfile.base: COPY + chmod, same pattern as dot-watch/studio-expose.
- scripts/smoke-test.sh: 4 new checks (binary present+executable, human
output has release tag, --json round-trips the manifest, --quiet is
a single line).
- README.md / AGENTS.md / CHANGELOG.md updated.
