It might actually turn out that if you were sitting on an unmaintained legacy app, the timing actually works out for you:), funny twist of fate. MCP servers now make the modernization path a lot more straightforward.
A tech journalist Paul Thurrott once published an open-source Notepad clone, NotepadWPF (https://github.com/thurrott/NotepadWPF) , as a way to examine modern Windows UI patterns. The NotepadWPF s was converted using AI from windows-only to a cross-platform app running on linux, mac, windows and Web in under three minutes. The AI system produced a functional modernized application which is 99% identical to the original. Original app and source code was used to feed AI – the resulting video is here - https://youtu.be/7-l_ZsZdIb0. AI is from https://github.com/unoplatform/uno