pundit: convert uploads to pundit.

app/policies/upload_policy.rb

@@ -0,0 +1,19 @@
+class UploadPolicy < ApplicationPolicy
+  def batch?
+    unbanned?
+  end
+
+  def image_proxy?
+    unbanned?
+  end
+
+  def preprocess?
+    unbanned?
+  end
+
+  def permitted_attributes
+    %i[file source tag_string rating status parent_id artist_commentary_title
+       artist_commentary_desc include_artist_commentary referer_url
+       md5_confirmation as_pending translated_commentary_title translated_commentary_desc]
+  end
+end