Serve system user avatar as an asset

app/controllers/users/avatars_controller.rb

@@ -8,7 +8,7 @@ class Users::AvatarsController < ApplicationController
 
   def show
     if @user.system?
-      redirect_to "/apple-touch-icon.png"
+      redirect_to view_context.image_path("system_user.png")
     elsif @user.avatar.attached?
       redirect_to rails_blob_url(@user.avatar.variant(:thumb), disposition: "inline")
     elsif stale? @user, cache_control: cache_control

test/controllers/users/avatars_controller_test.rb

@@ -9,7 +9,7 @@ class Users::AvatarsControllerTest < ActionDispatch::IntegrationTest
     get user_avatar_path(users(:system))
 
     assert_response :redirect
-    assert_redirected_to "/apple-touch-icon.png"
+    assert_redirected_to ActionController::Base.helpers.image_path("system_user.png")
   end
 
   test "show own initials without caching" do