Reorganize as an umbrella directory managing independent sub-project repos
(discord-app-v2, database, sba-website). Adds umbrella CLAUDE.md with
architecture diagram and deployment topology, .gitignore for sub-projects,
and skeleton ROADMAP.md. Legacy files archived, old website and root
docker-compose removed.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
