Final PRD 0023 chunk. The PRD 0022 attack suite was already
backend-agnostic — it goes through get_bottle_backend(), so the
right dispatch happens based on CLAUDE_BOTTLE_BACKEND. Two
cleanups to make it actually run cleanly under
CLAUDE_BOTTLE_BACKEND=smolmachines:
- setUpClass raises unittest.SkipTest with a useful message when
CLAUDE_BOTTLE_BACKEND=smolmachines but smolvm isn't on PATH, or
when the host isn't macOS (libkrun + TSI single-IP allowlist is
macOS-only in v1). Without this, the test would die deep inside
backend.prepare's smolmachines_preflight rather than skipping.
- test_5_readme_push_blocked switches from a hardcoded
`git://git-gate/...` remote URL (only resolvable on docker via
the bundle's short alias) to the bottle's declared upstream URL
(`ssh://git@unreachable.invalid:22/throwaway.git`). The agent's
~/.gitconfig insteadOf rewrite — set up by provision_git on both
backends — transparently redirects to the gate, so the same test
exercises docker's `git://git-gate/...` and smolmachines's
`git://<bundle_ip>:9418/...` URLs without branching on backend.
README gets a "Backend selection" subsection under Quickstart
documenting CLAUDE_BOTTLE_BACKEND, the macOS-only v1 scope for
smolmachines, and the `curl -sSL .../install.sh | sh` install
prerequisite — per PRD 0023's acceptance criteria.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>