Reconcile only untouched baseline theme seeds after an accepted newer
legacy terminal winner. Protect explicit native choices, edits, tombstones,
and same-batch native selections while preserving stable IDs and rollback.
Keep materialized theme ordering consistent with persisted loads. Require
complete-envelope equality before clearing a live saved record's pending
upload so stale acknowledgements cannot discard a changed baseline seed.
Hoist V6/V7 peer-key validation instead of rebuilding groups per key.
Validation: 143 focused persistence, sync, transport, and host tests passed,
including disk reopen, rollback, two-store propagation, and stale ACKs.