Write the three required documentation files for the nbd crate:
- README.md: usage guide, field reference, dev workflow, dual-license
footer, and Claude Code disclaimer
- docs/PLANNING.md: development phase log and post-MVP roadmap
- docs/ARCHITECTURE.md: module responsibilities, data flow diagram,
storage layout, and testing strategy
Run and verify cargo fmt, check, clippy, and test (34 tests pass).
Mark all Phase 6 items as complete in PLAN.md.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Elijah Voigt