upsertNode method
Insert or update a node. On conflict (same nodeId), the existing
row is unconditionally overwritten with the incoming data.
Important: This method does NOT enforce freshness — callers are
responsible for checking whether the incoming data is newer before
calling this method. The AirpassSyncEngine._mergeNodes method
performs this check by comparing lastSeen timestamps.
Implementation
Future<void> upsertNode(NodesCompanion entry) async {
await into(nodes).insertOnConflictUpdate(entry);
}