feat(api): tcp driver registry, identify, preset push delivery

- Track Wi-Fi TCP clients, liveness pings, disconnect broadcast, bind errors via gather\n- Device list/get include connected; POST identify with __identify preset\n- Presets push/send delivery helpers; bump led-driver hello type

Made-with: Cursor

tests/tcp_test_server.py

@@ -6,8 +6,8 @@ Listens on the same TCP port used by led-driver WiFi transport and
 every 5 seconds sends a newline-delimited JSON message with v="1".
 
 Clients talking to the real Pi registry should send a first line JSON object
-that includes device_name and mac (12 hex) so the controller can register
-the device by MAC.
+that includes device_name, mac (12 hex), and type (e.g. led) so the controller
+can register the device by MAC.
 """
 
 import asyncio