Add BLE host transport selectable via DIP8 alongside UART.

Master can speak the same framed protobuf protocol over NimBLE or UART; goTool gains -ble, ble-rtt, and ble-stream timing checks for ESP-NOW coexistence.

Co-authored-by: Cursor <cursoragent@cursor.com>

main/CMakeLists.txt

@@ -12,6 +12,9 @@ idf_component_register(
   "powerpod.c"
   "led_ring.c"
   "uart.c"
+  "host_transport.c"
+  "ble_host.c"
+  "ble_stream.c"
   "uart_proto.c"
   "uart_cmd.c"
   "cmd/cmd_handler.c"
@@ -59,6 +62,7 @@ idf_component_register(
   esp_netif
   esp_event
   nvs_flash
+  bt
   PRIV_REQUIRES
   esp_driver_gpio
   esp_driver_uart