Make "Navigate data" default screen

When a user opens the app they must immediately see their resource space and tag selector. They should use folders screen only for setting up and sometimes for quicker navigation but only if we missed some features. Ideally, all navigation should happen with tags.

The exception is when user doesn't have any folders and added only empty folders — then we should inform them about it and open folders screen.

No files, tests, or entry points are named. Start by running the app and reproducing the current startup flow, then inspect how folders and the Navigate data screen are selected. Done means users with resources see their resource space and tag selector first, while users with only empty folders are informed and taken to the folders screen.

Written by the indexing model from the issue text.