Every time I restart BookyAI, the AI engine goes back to Gemini. How do I make my engine the default?

This is fixed in version 1.9.23. BookyAI now remembers the engine you choose last: when you create a book with it, change a book's engine in Book details, click an engine in New Book, or pick one in an Activity studio. After a restart, New Book, imported books, the Activity studios and Settings all start on that engine, as long as it is still connected (its key saved, or Ollama running). If it is not connected any more, BookyAI starts on the engine of your newest book, and then on the first connected one.