Add an /avatars/#UserId route which redirects to the user's current avatar every time, so you don't need to update remote references to it

src/Handler/Avatars.hs

@@ -0,0 +1,12 @@
+{-# LANGUAGE NoImplicitPrelude #-}
+{-# LANGUAGE OverloadedStrings #-}
+module Handler.Avatars where
+
+import Import
+
+import Model.Cache ( getCached )
+import Settings.StaticR ( staticR ) 
+
+getAvatarR :: UserId -> Handler ()
+getAvatarR = redirect <=< fmap (avatarR . entityVal) . getCached
+    where avatarR user = staticR ["img", userAvatar user]