Optional scopeThe form of the brain's user and persona scope ids when the snapshot was read: 'encoded' once a learning
layer re-filed the brain (SCOPE_ID_FORM_KEY), else 'plain'. Memory.restoreTrace writes a plain
snapshot into a brain re-filed since under the encoded id, as the re-file wrote the row: there a plain id that
holds a / reads as a namespaced user's (team/ana names user ana of namespace team). Unset, a restore writes
the scope id as the snapshot holds it.
A
memory_tracesrow as a ledger row's before-state holds it: every column but the embedding. A restore keeps the row's embedding where the row holds the snapshot's content (writeTraceSnapshot); a trace restored to other content regains a vector when it is next written (asmemory_updateclears it when the content changes).