feat(02-02): implement ESP32Transport UDP client with asyncio DatagramProtocol

- ESP32Transport.send_command() injects v:1, fire-and-forget, silent drop if not ready
- 512-byte payload limit enforced with warning log
- datagram_received() parses STATUS ok → connected=True, stores last_status
- on_status callback support for status update notifications
- connection_lost() sets connected=False, clears transport ref
- create_esp32_transport() async factory sends initial STATUS ping (D-12)
- All protocol behaviors match docs/protocol.md exactly (D-10, D-11, D-12, D-14)
- Add pytest-asyncio to dev deps + asyncio_mode=auto for test suite

src/led_sync/__init__.py

@@ -0,0 +1 @@
+__version__ = "0.1.0"