So this was a slightly wrong error message, what was happening was:
1. Trying to load the image hash for this pet, by looking them up at
https://pets.neopets.com/cpn/PET_NAME/1/1.png and seeing what URL it
redirects to.
2. But pets.neopets.com was rejecting our User-Agent string, which
would've been just "Ruby", since we hadn't set it otherwise. I guess
that's an explicitly banned string?
I also found that the kind of more-helpful User-Agent string I like to
write was being rejected, and I could only get it to accept something
very simple? So that's what we're using now, I guess!!
I noticed when running `rails routes` that there's a lot of routes for
major unused Rails features, like storage. I didn't look deeply enough
into ActiveStorage to know if I was risking accepting arbitrary file
uploads, I just figured, if I disable it (which simplifies the app
footprint anyway), then I can be certain! So, goodbye!
The usual stuff! Installed the new gem and its new deps, ran
`bin/rails app:update` and did my best to manually merge the dev/prod
config files with the new canonical defaults, deleted some migrations I
don't think are relevant to us, and yeah!
Also, Rails 7.1 seems to need `libyaml-dev` installed, so I added that
to the `deploy/setup.yml` playbook!
One thing to note is that, while I was here, I turned on some settings
relating to our use of SSL that technically weren't on before. This
should be fine and helpful? But if stuff breaks, well, check those!
Whew! Seems like a pretty clean one? Ran `rails app:upgrade` and stuff, and made some corrections to keyword arguments for `translate` calls. There might be more such problems elsewhere? But that's hard to search for, and we'll have to see.
This one was pretty straightforward yaay! Main thing was the change from `render file` to `render template` in a couple places, oh and a thing with complex `order()` clauses.
Some important little upgrades but mostly straightforward!
Note that there's still a known issue where item searches crash, I was hoping that this was a bug in Rails 4.2 that would be fixed on upgading to 5, but nope, oh well!
Also uhh I just got a bit silly and didn't actually mean to go all the way to 5.2 in one go, I had meant to start at 5.0… but tbh the 5.1 and 5.2 changes seem small, and this seems to be working, so. Yeah ok let's roll!
Idk this one might actually be a bit of a pain to load? But I'd want to optimize it differently anyway, and there's overhauls we're already planning to do here.
NOTE: This doesn't boot yet! There's something changed in the `devise` API that we'll need to fix!
```
/vagrant/config/initializers/devise.rb:46:in `block in <top (required)>': undefined method `encryptor=' for Devise:Module (NoMethodError)
```
But yeah, we navigated the gem upgrades, and also I ran `rake rails:update` and hand-processed the suggestions it had for our config files.