Changing SQLite database encoding in AIR app to UTF-8
With no other workarounds or answers found, I'm posting my workaround as the Answer. It worked fine in a PlayBook app for the last two years, so presumably has no unforeseen side-effects, at least in that environment:
My workaround for now is to use a "template.db" that I create ahead of time and bundled into the application. In this template.db I've set the encoding to UTF-8 manually. If the database file does not exist already when my program starts, I create it by copying that template to my database file, then proceed to open and use it normally. I've confirmed that TEXT data then now stored as UTF-8 as desired.