FiXPro v2.0.20260404145308

refactor: Complete project refactoring

Firmware:
- Refactored main.cpp with modular structure
- Added config.h with pin definitions and constants
- Added commands.h/cpp with command handlers
- Added proper version management (v2.1.0)

Quality Assurance:
- Added comprehensive protocol tests (23 tests)
- Added CI/CD quality checks workflow
- Added pre-commit hooks
- Added CONTRIBUTING.md guidelines

Tests:
- Added Python unit tests for protocol
- Test coverage for command parsing
- Test coverage for response formats
- Test coverage for error handling