This happens for example if we access "/dbp-signature.html" in which case the
router interprets the file name as a language.

Register the activity properly and create a scoped element if the API is there.

One all bugs are fixed upstream this should allow us to switch to lit v2
without any further changes.

See issue #33

See issue #33

Instead of handling the visibility checks at render time we keep around a list
of visible routes and emit an event when they change. This way the welcome activity
can mirror what the menu shows and update at the same time.

This field specifies a list of roles that the logged-in user needs to
have to interact with this activity.

In the case of the app-shell this means the activity is hidden until
the user information is loaded after login.