Add STATE.scm project checkpoint file (#32)

Creates a comprehensive state checkpoint following the state.scm format
(https://github.com/hyperpolymath/state.scm) documenting:

- Current position: v0.4.0 with RSR Bronze compliance
- Critical blockers: v0.4 license text is stub, Council not formed
- Route to MVP v1.0: dependency graph and phased milestones
- Issues: 7 tracked issues (2 critical, 3 major, 2 minor)
- Questions for maintainers: 7 items needing clarification
- Long-term roadmap: 5-year plan through 2030

This enables AI-assisted development sessions to maintain context across
conversations.

Co-authored-by: Claude <noreply@anthropic.com>

Author: hyperpolymath