A logical snapshot restore could silently lose graph edges on a brain backed by
a native provider: the graph adjacency keys on the shared id-mapper's interned
ints (sourceInt/targetInt), which are derived + never persisted, and restore()
never reloaded the mapper — so a native graph rebuild resolved verb endpoints
against a stale/empty mapper and dropped edges.
restore() now calls entityIdMapper.rebuild() — a new OPTIONAL method on the
EntityIdMapperProvider contract — BEFORE rebuilding the indexes, so a native
mapper reloads its int<->uuid from the restored binary KV first and the graph
resolves endpoints correctly. The JS mapper deliberately has NO rebuild() and
needs none: MetadataIndex.rebuild() re-derives it from the restored entities via
append-only getOrAssign, consistently with the bitmaps it builds — forcing a
reload there would blank a still-referenced mapping and break find() after a
same-instance restore.
Contract: graphIndex.rebuild() resolves sourceId/targetId -> ints through the
shared mapper itself (brainy does not re-feed resolved endpoints); brainy's only
job is to ensure the mapper is reloaded first.
Test: relationships survive a snapshot round-trip (db-mvcc.test.ts). 84
generation/temporal/visibility tests green; tsc clean.