Activate the completed generation; old cursors immediately become stale.
Backfill canonical snapshots idempotently into the building generation.
Idempotently add one canonical document to the building generation.
Open a separate building generation; ordinary writers then dual-write.
Load the current generation pointer, synthesizing the normal active generation.
Physically reclaim an inactive generation after its zero-retention switch.
Explicit lifecycle operations for occupancy rebuilds and activation.