Remove "under construction" from home page

[gnprice]

The app's home screen has the text:

🚧 Under construction 🚧

That was accurate when I wrote it, when the app was a prototype less than an hour old (c4ede10fdb729ddc5e22845252afb3539085fe01, 00c09d597c60d1f9b14f71bf41f5eb8e7ec5334b). But it doesn't fit so well now.

We should cut that and some of the other data on that screen that isn't relevant for the user.

Mentioned in chat here: https://chat.zulip.org/#narrow/stream/48-mobile/topic/Flutter.20app.20.2B.20SAML.20auth/near/1774010