Clean up the navigation

[teelur]

Now that the UI has matured a bit, it would be nice to go over the navigation:

• Currently there is only one /dashboard endpoint when authorized. Maybe it should be split up between the different pages?
• Currently every secondary interface is stuck in a modal. Some of these are complex enough that they probably should be pages.
• These new pages could probably use some sidebar/tabbed interface vs just a giant list of accordion sections.

Overall the goal is to make use of screen real estate better, and try to make the UI more consistent.