Add simple admin overview of PuSH subscriptions

app/controllers/admin/pubsubhubbub_controller.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+class Admin::PubsubhubbubController < ApplicationController
+  before_action :require_admin!
+
+  layout 'public'
+
+  def index
+    @subscriptions = Subscription.includes(:account).paginate(page: params[:page], per_page: 40)
+  end
+end

app/controllers/application_controller.rb

@@ -31,6 +31,10 @@ class ApplicationController < ActionController::Base
     I18n.locale = I18n.default_locale
   end
 
+  def require_admin!
+    redirect_to root_path unless current_user&.admin?
+  end
+
   protected
 
   def not_found