Use cached compatible body IDs on homepage modeling code

This should make it load way faster! Maybe don't even need to mess with
caching the resulting HTML anymore, like we currently do?

app/controllers/outfits_controller.rb

@@ -52,7 +52,8 @@ class OutfitsController < ApplicationController
 
     # HACK: Skip this in development, because it's slow!
     newest_items = Item.newest.
-      select(:id, :name, :updated_at, :thumbnail_url, :rarity_index, :is_manually_nc)
+      select(:id, :name, :updated_at, :thumbnail_url, :rarity_index,
+             :is_manually_nc, :cached_compatible_body_ids)
       .limit(18)
     @newest_modeled_items, @newest_unmodeled_items =
       newest_items.partition(&:predicted_fully_modeled?)

app/models/item.rb

@@ -262,7 +262,7 @@ class Item < ApplicationRecord
 
   def update_cached_fields
     self.cached_occupied_zone_ids = occupied_zone_ids
-    self.cached_compatible_body_ids = compatible_body_ids
+    self.cached_compatible_body_ids = compatible_body_ids(use_cached: false)
     self.save!
   end
 
@@ -376,7 +376,9 @@ class Item < ApplicationRecord
     }.merge(options))
   end
 
-  def compatible_body_ids
+  def compatible_body_ids(use_cached: true)
+    return cached_compatible_body_ids if use_cached
+
     swf_assets.map(&:body_id).uniq
   end