IMO, shared utils must be a library, like:

    features
        auth
            login
    libraries
        dates
        strings
        ...

I don't like to have a package / library called `utils`, `commons`, `shared` and other generic words that does not indicate me what's the context of this folder.

Why not both?

Move your pure function utilities to a feature-agnostic folder whenever it makes sense, and import them into your feature.

I agree that's where the problems begin though :)

    feature/shared/utils/foo.ts
    feature/shared/utils/format-date.ts
    feature/shared/ux/(template|region|etc)/foo.ts

Where ux are for components that may be referenced in multiple areas, or generic templates, etc. and shared are for utility methods, functions, etc.

In a commons folder?