tap-wake: re-check the screen on taps while 'awake'

If something else turned the screen off during the wake minute (the
9pm cron, a kiosk restart from an update), taps only extended the timer
and never turned it back on, so it stayed dark until nobody touched it
for a full minute. Now every tap (at most every 2s) checks the real
screen state.

bin/tap-wake.py

@@ -49,8 +49,9 @@ while True:
         os.read(fd, 4096)
         if wake_until is not None:
             wake_until = now + AWAKE_SECONDS            # keep it on while being used
-        elif now - last_check > 2:                      # a swipe is lots of events; check once
+        if now - last_check > 2:                        # a swipe is lots of events; check every 2s
             last_check = now
+            # check even while "awake": cron or a kiosk restart may have turned it off under us
             if screen_is_off():
                 subprocess.run([SCREEN, "dim"], env=ENV)
                 wake_until = now + AWAKE_SECONDS