[contursofran]

Summary

• preserve the original desktop and Arduino sources under legacy
• add a safe Python 3 CLI for cube validation, Kociemba solving, and protocol encoding
• add an Arduino protocol test sketch that does not move hardware
• document architecture, hardware limits, known legacy defects, and public archive status
• add an MIT license and GitHub Actions test workflow

Validation

• 13 unit tests pass
• Python source compiles
• editable package installs with solver and serial extras
• dry-run CLI and solved-state path pass
• pip dependency check passes
• firmware test sketch passes clang-format validation
• current tree and full Git history contain no secret-like files in the audit scan

Scope

The historical camera GUI and motion firmware are preserved without code changes. Exact restoration of the old hardware behavior is not part of this archival update.