It's a nice feature, I agree with @hestro on that. However, if this is too much trouble to integrate into the website it might be worth atleast pausing until the criteria of milestone 3 is met. That being said, if this is something you like to work on, I'm not going to stop you from it.

Missing VITE_APP_URL fails silently with “Invalid callbackURL”. callbackURL is built as ${import.meta.env.VITE_APP_URL}/project2/. Without frontend/.env, it becomes undefined/project2/, and better-auth rejects it with a 403. Nothing in the UI says why. Suggest either import.meta.env.VITE_APP_URL ?? window.location.origin, or better, a relative callbackURL: import.meta.env.BASE_URL so no extra env variable is needed. Also show a toast when signIn.social returns an error, and document VITE_APP_URL in deployment.md.

AI generated comment ^

We cannot have a relative link like that, since that would send us to the backend at port 3001 after the login at GitHub/Discord is done. That's why we need to build a full link.

However, thanks for mentioning the issue that comes up if the environment variable is not defined. I have now explicitly documented this, and the fallback you mention with using window.location.origin is implemented in 1f5f82f

The issues mentioned should be fine, and I also provided some documentation in aa0a6a6 so it should be easier to test. Let me know if you guys encounter any difficulties

@hestro Could you approve this again? Needed to resolve a merge conflict before merging.