1fa17d1822
Replaces the alpine:latest placeholder with a real claude-bottle agent image, converted into a .smolmachine artifact via an ephemeral local OCI registry. Why the registry hop: smolvm pack create only accepts OCI registry refs. Empirically it rejects docker-daemon://, oci-layout://, docker-archive: tarballs, and every other transport tested — the crane backend treats anything with a scheme prefix as a registry hostname. To convert a locally-built docker image into a .smolmachine we have to push it somewhere smolvm can pull from. Smallest path: bring up registry:2.8.3 bound to 127.0.0.1:<random>, docker tag + docker push into it, smolvm pack create --image localhost:<port>/claude-bottle:<id>, tear down the registry. The .smolmachine is cached under ~/.cache/claude-bottle/smolmachines/ keyed by the docker image ID (first 16 hex chars of the sha256), so a Dockerfile change picks up a new image ID and invalidates the cache. Unchanged rebuilds skip the whole build → registry → pack pipeline. This puts `docker build` in smolmachines prepare (the docker backend defers it to launch). Necessary because pack_create needs the image ID to derive the cache key, and prepare is the only hook ahead of launch that runs once per slug. Adds: - claude_bottle/backend/docker/util.py: image_id / tag / push helpers (thin docker CLI wrappers). - claude_bottle/backend/smolmachines/local_registry.py: ephemeral_registry() context manager; pins registry:2.8.3 by digest, binds 127.0.0.1::5000 (loopback-only), force-removes on exit. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>