- Add utun VPN daemon with config parsing, control socket, routing, and TUN interface
- Refactor net_emulator/u_async to support multiple independent instances
- Replace linked-list timeout management with heap-based implementation
- Fix timeout processing bug (process timeouts after select)
- Add comprehensive random timeout and instance isolation tests
- Update Makefile to build utun and new test targets
- Implement queue_wait_threshold() with automatic waiter checking in ll_queue
- Add pkt_normalizer_flush() to force buffer sending
- Enhance test suite with async wait tests, fragmentation verification, and buffer flush tests
- Fix test edge cases by flushing packer buffer between subtests
- Improve test reliability with increased iteration limits and while loop processing
- Add connection module for secure UDP communication with ECC/AES-CCM cryptography
- Move all test files to tests/ directory
- Update Makefile to build tests in tests/ directory
- Add fragment reassembly timeout mechanism (500ms default)
- Add error count API (pkt_normalizer_get_error_count, pkt_normalizer_reset_error_count)
- Enhance error handling with timeout callbacks
- Add comprehensive stress tests and edge case tests
- Update .gitignore for build artifacts