Root cause of demo_composition pin thrash was not cancelled CI runs:
verify_no_global_state_mutation dumped full env_subset before/after
tuples into the lane report, embedding CORE_ENGINE_STATE_DIR temp
paths (and any ambient CORE_* host values). Each hermetic run then
produced a different report SHA.
Fix for good:
- Report key-level env deltas only (+/- / changed), with path-like
CORE_* values redacted to <path> in the message text.
- Detection still uses raw snapshots (mutations are not ignored).
- Hermetic CORE_ENGINE_STATE_DIR for demo_composition and all
verify_lane_shas invocations.
- Dual-run-stable re-pin: demo_composition e2ba2314…,
public_demo 7d8ba0db… (matches CI-observed soft-budget SHA).
- Drop dead CORE_SHOWCASE_SKIP_BUDGET workflow env (soft is default).
- Tests pin the delta format and hermetic-path stability.
Lane: python scripts/verify_lane_shas.py → 9/9 match.
7f6c497a21