- 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
- Implement Extended Transmission Control Protocol (etcp.c/h) for reliable
UDP transmission with packet ordering and loss recovery
- Add window management (congestion control) with dynamic window sizing
based on RTT and bandwidth
- Implement ACK handling, retransmission logic, and gap detection
- Add comprehensive test suite: unit tests, simple test, and stress test
with network emulation (packet loss, reordering, delay)
- Include mock u_async implementation for testing
- Update Makefile with new ETCP build targets