Research: Neo4j Aura setup + free tier limits

[krapfj23]

Summary

Evaluate Neo4j Aura's free tier and verify Cognee's Neo4j integration works.

Blocked by

Nothing — this is a starting ticket.

Blocks

• Migrate graph store config: Kuzu → Neo4j Aura #66 (migrate graph store config)

Steps

1. Create a free Neo4j Aura account and provision a free-tier instance
2. Document: node/relationship limits, storage limits, query limits, connection string format
3. Test connecting from a local Python script using neo4j driver
4. Verify Cognee's Neo4j support: install cognee[neo4j], set GRAPH_DATABASE_PROVIDER=neo4j and connection vars, run a minimal cognee.add() + cognee.cognify()
5. Document any gotchas (version compatibility, required plugins, Bolt vs Neo4j protocol)

Acceptance Criteria

• docs/neo4j-aura-research.md exists
• Free tier limits documented
• Cognee + Neo4j tested with a real cognify() call
• Connection string format documented
• PR body includes Closes #65