Add PollingReceiverWorker class to handle inbox processing

lib/inboxable/polling_receiver_worker.rb

@@ -0,0 +1,18 @@
+module Inboxable
+  class PollingReceiverWorker
+    include Sidekiq::Job
+
+    def perform
+      perform_activerecord
+    end
+
+    def perform_activerecord
+      Inbox.pending.where(last_attempted_at: [..Time.zone.now, nil]).find_in_batches(batch_size: ENV.fetch('INBOXABLE__BATCH_SIZE', 100).to_i).each do |batch|
+        batch.each do |inbox|
+          inbox.processor_class_name.constantize.perform_async(inbox.id)
+          inbox.update(last_attempted_at: 1.minute.from_now, status: :processing, allow_publish: false)
+        end
+      end
+    end
+  end
+end

sig/inboxable/polling_receiver_worker.rbs

@@ -0,0 +1,7 @@
+module Inboxable
+  class PollingReceiverWorker
+    def initialize: -> void
+    def perform: -> void
+    def perform_activerecord: -> void
+  end
+end