chore(cheatsheet): trailing-newline tidy from the print pass

Whitespace only — PLN opened docs/GIG-CHEATSHEET.md to send it to his phone
and print it for the rehearsal, and the save stripped the trailing blank line.
Committing it so the tree is clean before travel: an unexplained dirty file is
exactly the shape a Pulsar buffer-clobber leaves behind, and the next session
should not have to re-derive that this one was benign.

docs/GIG-CHEATSHEET.md

@@ -105,4 +105,3 @@ and `gF<N>` carrying different numbers on the same orbit is CORRECT.
 An orbit a track does **not** declare is not silent by default — it keeps
 playing whatever the previous track put there. When a transition sounds
 wrong, that is the first thing to suspect.
-