Make sure jobs are enqueued only after all transactions are committed

This should fix the recurring ActiveStorage::FileNotFoundError errors
from ActiveStorage::AnalyzeJob.

The issue is that, when images are not direct uploaded (e.g. a card
background image or avatar image), the AnalyzeJob has been getting
enqueued before the file itself was uploaded to blob storage.

Setting ActiveJob::Base.enqueue_after_transaction_commit = true makes
sure that jobs are always enqueued only once *all* transactions have
been committed.

This will be the Rails default at some point, but for now we still
need to explicitly set it.

Big thanks to @jeremy for the assist. 👏

config/initializers/active_job.rb

@@ -6,6 +6,7 @@ module FizzyActiveJobExtensions
 
   prepended do
     attr_reader :account
+    self.enqueue_after_transaction_commit = true
   end
 
   def initialize(...)