Neo4j alternatives: test graph traversals and write semantics

For Neo4j alternatives, build a representative graph with the relationships the application queries most.

1. Import nodes, edges, properties, and uniqueness rules.
2. Recreate the top path, neighborhood, and aggregation queries.
3. Compare results and p95 latency during concurrent updates.
4. Test transaction rollback, index behavior, backup, and restore.
5. Estimate query-language rewrite and data-export effort.

A storage engine can hold the same edges yet answer traversals differently. Validate semantics and operational recovery, not just import speed.