remove post-release debug hax, whoops
fix audio bug by delaying 3us

and increase the melody stage duration accordingly.

apparently not using dtack was the reason, datasheet: "with respect to
amplitude data, a number of wait cycles may need to be performed"

.. of course the code "should" obey the dtack pin
better "random"
fix off-by-one bug of lagging visuals
post-party doc