Replace in-memory Maps with persistent PostgreSQL storage:
- Add db.ts with typed query functions for users, credentials, challenges
- Add schema.sql with users/credentials/challenges tables
- Update server.ts to use async DB queries
- Add postgres service to docker-compose
- Health endpoint now reports database connectivity
- Auto-cleanup of expired challenges every 10 minutes
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Jeff Emmett
e5af01119b