Fix "couldn't download the associated Flash files" when modeling

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!!

app/models/pet_type.rb

@@ -126,9 +126,11 @@ class PetType < ApplicationRecord
 
   before_save do
     if @origin_pet && @origin_pet.name =~ IMAGE_CPN_ACCEPTABLE_NAME
-      cpn_uri = URI.parse sprintf(IMAGE_CPN_FORMAT, CGI.escape(@origin_pet.name));
+      cpn_uri = URI.parse sprintf(IMAGE_CPN_FORMAT, CGI.escape(@origin_pet.name))
       begin
-        res = Net::HTTP.get_response(cpn_uri)
+        res = Net::HTTP.get_response(cpn_uri, {
+          'User-Agent' => Rails.configuration.user_agent_for_neopets
+        })
       rescue Exception => e
         raise DownloadError, e.message
       end

config/application.rb

@@ -60,6 +60,12 @@ module OpenneoImpressItems
     config.assets.initialize_on_precompile = false
 
     config.middleware.insert_after ActionDispatch::Flash, Rack::Attack
+
+    # It seems like some Neopets servers reject any user agent containing
+    # symbols? So I can't provide anything helpful like a URL, email address,
+    # version number, etc. So let's only send this to Neopets systems, where it
+    # should hopefully be clear who we are from context!
+    config.user_agent_for_neopets = "Dress to Impress"
   end
 end
 

config/locales/en-MEEP.yml

@@ -676,7 +676,8 @@ en-MEEP:
       not_found: We couldn't meep a pet by that name. Is it meeped correctly?
       asset_download_error:
         We meeped the pet and what it's wearing, but couldn't meep the
-        associated Flash files. Maybe Neopets is down. Please meep again later!
+        associated meepia files. Maybe Neopets is down, or changed their
+        firewall rules? Please meep again later!
       pet_download_error:
         We couldn't meep to Neopets to meep up the pet. Maybe they're down.
         Please try meep later!

config/locales/en.yml

@@ -751,7 +751,8 @@ en:
       not_found: We couldn't find a pet by that name. Is it spelled correctly?
       asset_download_error:
         We found the pet and what it's wearing, but couldn't download the
-        associated Flash files. Maybe Neopets is down. Please try again later!
+        associated media files. Maybe Neopets is down, or changed their
+        firewall rules? Please try again later!
       pet_download_error:
         We couldn't connect to Neopets to look up the pet. Maybe they're down.
         Please try again later!

config/locales/es.yml

@@ -533,7 +533,7 @@ es:
         submission_success: "%{points} puntos"
     load:
       not_found: No hemos podido encontrar a un pet con ese nombre. ¿Lo has escrito correctamente?
-      asset_download_error: Hemos encontrado el pet que intentas vestir, pero no hemos podido descargar las imágenes flash que lo asocian. Posiblemente Neopets está caído. ¡Por favor inténtalo de nuevo más tarde!
+      asset_download_error: Hemos encontrado el pet que intentas vestir, pero no hemos podido descargar las imágenes que lo asocian. Posiblemente Neopets está caído. ¡Por favor inténtalo de nuevo más tarde!
       pet_download_error: No hemos podido conectar con Neopets para ver tu pet. Posiblemente el servidor de Neopets se ha caído. ¡Por favor inténtalo de nuevo más tarde!
   users:
     index: