techo_ui: implement poweroff + led fixes

variants/techo/variant.cpp

@@ -24,6 +24,8 @@ void initVariant() {
   pinMode(LED_GREEN, OUTPUT);
   pinMode(LED_BLUE, OUTPUT);
   digitalWrite(LED_BLUE, HIGH);
+  digitalWrite(LED_GREEN, HIGH);
+  digitalWrite(LED_RED, HIGH);
 
   pinMode(PIN_TXCO, OUTPUT);
   digitalWrite(PIN_TXCO, HIGH);