lib/transcript-consent.ts reads transcript_ingest_mode and transcript_repos
together from every merged state root and returns one policy: off in any
root is off, cutoffs and 90-day windows stack, allowlists intersect (EMPTY
denies), and a +repos marker without a readable allowlist denies. It also
owns the per-session and per-page scope checks, the staged-page purge and
the unpublished-range guard, with a --check/--describe/--purge/
--guard-unpublished CLI for gstack-brain-sync. state-root exports its
per-root key reader; transcript_ingest_mode stays out of MERGED_CONFIG_KEYS.