transition_to_frozen and transition_to_unfrozen no longer touch YAML; both
now just call apply_transition with no content_transform. Pairs with the
stage-6 read-side change in projection.rs.
Story 934 will obviate the entire resume_to mechanism by making frozen a
flag orthogonal to Stage (story stays in its current Stage when frozen).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Timmy
dave