Add command queue dispatcher and VERSION UART handler.

Centralize command dispatch over a FreeRTOS queue so UART and future
ESP-NOW transports can register handlers; implement the protobuf VERSION
command with framed nanopb responses including build git hash.

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

main/uart_proto.h

@@ -0,0 +1,9 @@
+#ifndef UART_PROTO_H
+#define UART_PROTO_H
+
+#include "esp_err.h"
+#include "uart_messages.pb.h"
+
+esp_err_t uart_send_uart_message(const alox_UartMessage *msg);
+
+#endif