This commit enhances the logging system with better thread safety and proper test configuration:
- Replace RefCell with RwLock in SimpleLogger for thread-safe logging
- Add proper feature flag configuration for test-sync
- Organize logging modules with clear separation between prod and test
- Update test files with proper feature flag annotations
- Fix module structure in lib.rs to avoid duplicate definitions
Technical changes:
- Use RwLock for thread-safe log writer access
- Add #![cfg(feature = "test-sync")] to all test files
- Configure .cargo/config.toml for test-sync feature
- Update Cargo.toml with proper test configurations
- Clean up logging module exports
This change ensures thread-safe logging in production while maintaining
separate test-specific synchronization primitives, improving overall
reliability and maintainability.