Remove internal GOTCHA framework artifacts, GitLab registry references,
and infrastructure-specific values. Add community files (LICENSE,
CODE_OF_CONDUCT, CONTRIBUTING, SECURITY), GitHub Actions CI/CD workflows,
docker-compose.yml, and rewrite README for public consumption.

- Remove .beads/, .gotcha.yaml, AGENTS.md, internal design docs
- Add .gitignore entries to prevent re-adding internal files
- Replace internal registry/S3/CloudFront values with placeholders
- Remove unused next-auth dependency
- Add AGPL-3.0-or-later license field to package.json
- Add security warning about unauthenticated web UI
- Add CI workflow (lint + build) and Docker workflow (ghcr.io)

Co-Authored-By: Claude Opus 4.6 <[email protected]>