Oh right, we don't have Rails UJS going on anymore, which is what
handled the confirmation prompts for deleting lists. Turbo is the more
standard modern solution to that, and should speed up certain
pageloads, so let's do it!
Here I install the `turbo-rails` gem, then run `rails turbo:install` to
install the `@hotwired/turbo-rails` npm package. Then I move
`application.js` that's run all on pages but the outfit editor into our
section of JS that gets run through the bundler, and add Turbo to it.
I had to fix a couple tricky things:
1. The outfit editor page doesn't play nice with being swapped into the
document, so I make it require a full page reload instead.
2. Prefetching the Sign In link can cause the wrong `return_to` address
to be written to the `session`. (It's a GET request that does, ever
so slightly, take its own actions, oops!) As a simple hacky answer,
we disallow prefetching on that link.
Haven't fixed up the UJS stuff for confirm prompts to use Turbo yet,
that's next!
