Update suitbuilder documentation to reflect production-ready status
- Replace outdated CLAUDE.md suitbuilder section with concise production-ready summary
- Remove incorrect claims about spell system not being implemented
- Create detailed architecture document at docs/plans/2026-02-09-suitbuilder-architecture.md
- Document spell bitmap system, locked slots, suit summary, and SSE streaming
- Add future enhancement roadmap (spell improvements, new builders, advanced features)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>