R1:3fc03c0da106

Show magic "Home" menu item for logged-out users on public installs

Summary:
Ref T12174. Setup is:

- Allow public access.
- Don't touch the default menu.
- Visit `/` while logged out.

Currently, you see "magic home" as content, but don't actually see the menu item.

Instead, show the menu item.

Test Plan: {F2557000}

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T12174

Differential Revision: https://secure.phabricator.com/D17288