Does anybody know if there's an option in Coda somewhere (or a hack) that would sort folders at the top of the list in the file browsers?
I suspect that the File Browser sidebar is a standard Cocoa Widget. What this means is that it would follow all the same rules that standard OSX applications do (think: Finder).
Since the Finder does not show Folders first, Coda will probably not have a way to show Folder first.
I second Kris + Matthew B.'s answer, that Panic is a great company that answers users' questions. Having said that, don't get your hopes up, because Coda is just behaving exactly like the Finder does.