MACRAW IP stack with ARP/ICMP, stable device ordering, LED blink on test

firmware/include/net.h

@@ -1,3 +1,12 @@
 #pragma once
+#include <array>
+#include <cstdint>
+
+struct net_state {
+    std::array<uint8_t, 6> mac;
+    std::array<uint8_t, 4> ip;
+};
 
 bool net_init();
+const net_state& net_get_state();
+void net_poll();