Improve randomizer seeding

src/c/main.c

@@ -378,7 +378,13 @@ static void bluetooth_callback(bool connected) {
 // set up the app on launch (don't put app logic in here);
 static void init() {
 	// seed RNG
-	srand(time(NULL));
+	uint16_t seed_ms;
+	time_t seed_time;
+	time_ms(&seed_time, &seed_ms);
+	srand((unsigned int)seed_time ^ seed_ms);
+	rand();
+	rand();
+	rand(); // throw away first few values
 
 	// create main Window element and assign to pointer
 	s_main_window = window_create();