Move solid-queue dev setup to the engine

saas/config/environments/development.rb

@@ -2,4 +2,9 @@ Rails.application.configure do
   if Rails.root.join("tmp/structured-logging.txt").exist?
     config.structured_logging.logger = ActiveSupport::Logger.new("log/structured-development.log")
   end
+
+  if Rails.root.join("tmp/solid-queue.txt").exist?
+    config.active_job.queue_adapter = :solid_queue
+    config.solid_queue.connects_to = { database: { writing: :queue, reading: :queue } }
+  end
 end