BottlePlan gains a to_dict method (abstract on the base, implemented
on DockerBottlePlan) returning a JSON-serializable view of the resolved
plan. `cli.py start --dry-run --format=json` prints it to stdout and
exits zero. --format=json without --dry-run is rejected — emitting JSON
during a real launch would race the y/N prompt.
The dry-run integration test now parses the JSON and asserts on
structured fields (agent, bottle, runtime, hosts sorted+deduped, etc.)
instead of regex-matching the human-readable preflight stdout. That
kills the magic-"8 hosts allowed" coupling — adding a new baked
default doesn't break the test.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
didericis
beb0c9d58f