Addresses review comments 3098, 3099, 3100 on PR #336:
- Add BottleImages(agent, sidecar) dataclass to backend/__init__.py.
Docker/macOS backends use str image refs; smolmachines uses Path
artifacts. Replaces the singular `image` variable from the canonical
pattern in comment 3100.
- Replace _image_stale_checks/skip_stale with public prelaunch_checks().
CLI now calls backend.prelaunch_checks(plan) before backend.launch(plan);
if StaleImageError is raised and the operator confirms, launch proceeds
without re-checking. Removes the while-True/skip_stale retry loop.
- Add abstract _build_or_load_images(plan) -> BottleImages to
BottleBackend. launch() calls it then passes images to _launch_impl.
Each backend implements both methods.
- Fix comment 3098 (macos-container): _build_images is removed.
build_or_load_images() has separate fresh/cached code paths — the
cached path never calls a build helper.
- Update _start_bundle (smolmachines) to accept sidecar_artifact: Path
directly. Sidecar artifact resolution moves to _sidecar_from_path(),
called by build_or_load_images alongside _agent_from_path().
didericis-claude