deployment.yaml advanced past the one-shot rollout (P05/P06), so the helper
correctly refused it with prior_image_drift and existing_candidate_env. The
fixture now reconstructs the pre-rollout state, and a new test asserts the
helper refuses the current declaration.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Assistant: claude-code
Assistant-Model: opus
Assistant-Process: 299762@bnt-lap001
Assistant-Session: d3d3cea1-869c-44f1-be2a-3d6d3550e72e
