Move the --format=json-requires-dry-run check out of the integration
suite (it doesn't need Docker — argparse fails before any backend
runs) and tighten the assertion: previously asserted only that exit
code was nonzero, so any unrelated breakage (manifest resolution
failure, bad agent name, etc.) silently passed. Now asserts stderr
contains the actual flag-conflict message.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
