I'm thrilled that you're having fun with Decker; using it for nonlinear supplementary material for a webcomic is a really cool idea!
Swiping generates "navigation gestures", which are the touchscreen-accessible equivalent to navigating the deck with the cursor keys. By default, Decker includes this handler for navigate[] events:
on navigate x do if x~"right" go["Next"] end if x~"left" go["Prev"] end end
If you want to disable this, edit the deck-level script (File -> Properties... -> Script...) and add an empty handler:
on navigate do end
Note that while in Widgets mode or using any drawing tools you'll still be able to navigate between cards with left/right cursor keys; overriding navigate[] disables this functionality while in Interact mode.
There are, of course, other things one could do by overriding navigate[], like setting up fancy 2d movement through the deck or even making keyboard-based puzzle games!
Does that make sense?