Good stuff!
You can specify exactly a twelfth of a cycle in the mini-notation with "1%12" So that could be "0 1%12 2%12" etc. Alternatively you can specify it as "0 .. 11"/12, or using the run function, run 12/12.
To superimpose a copy of a pattern on top of itself with a pattern applied, you can use superimpose, e.g. d1 $ superimpose (twelfthPat <~) $ sound clapPat. I like jux, which is similar but pans the original and the transformed patterns hard left and right respectively.
resetCycles is inaccurate. There's also reset, so reset 1 retriggers the pattern when d1 is updated.
So here's my effort:
d1 $ reset 1 $ jux ((slow 144 $ run 12/12) <~) $ sound "cp!3 ~ cp! ~ cp ~ cp! ~"