Sign-in screens that look like the console

The authentication screens (sign-in, sign-up, forgot password, activation, email verification, invitation) show the Pierrr logo.
They also take the console's hexagon map backdrop: the way in now looks like what it opens.
The console sidebar and its mobile header show the full logo, mark included, instead of the bare name.

Hotfix 0.0.29-beta.1: the "Add an add-on" dialog still offered "Pier Agent". It now reads "Pierrr Agent".