Instead of renaming files to .txt, you should try Gemini 2.5 pro through OpenRouter with roo, Cline or using Github Copilot. I've been testing GH Copilot [0] and it's been working really well.
0: https://github.blog/changelog/2025-04-11-copilot-chat-users-...
I know perfectly I can use the API with any wrapper. I don't do that for choice, my human+AI development style is in the form of the chat, and since I discovered that many models behave differently (especially Gemini 2.5) based on where you invoke them (I don't know what Google is doing internally, if they change temperature / context size / ...) I stick with using the default way a model is provided to the public by a given provider. Besides, while I write a lot of code with the assistance of AI, my use case is mainly code reviews, design verification / brainstorming, and so forth, not much "write this code for me" (not that I believe there is anything wrong with it, just a matter of preferences -- I do it for things like tests, or to have a template when the coding task is just library calls that are boring to put together: typical use case, "generate the boilerplate to load a JPEG file with libjpeg"). So I keep using the web chat :)