Neo4j graph recovery after full wipe — schema + ETL bootstrap via admin API

After wiping the Neo4j database (AuraDB), the knowledge graph is completely empty — no constraints, no vector indexes, no nodes or relationships. The graph scripts (pnpm graph:schema:vectors, pnpm graph:migrate) are designed to run locally with direct NEO4J_URI/NEO4J_USER/NEO4J_PASSWORD env vars, but production runs on Railway where those env vars are already configured on the server. Running the scripts locally against prod requires leaking credentials.