Add more instance stats APIs (#6125)

* Add GET /api/v1/instance/peers API to reveal known domains

* Add GET /api/v1/instance/activity API

* Make new APIs disableable, exclude private statuses from activity stats

* Fix code style issue

* Fix week timestamps

app/models/user.rb

@@ -122,9 +122,19 @@ class User < ApplicationRecord
     update!(disabled: false)
   end
 
+  def confirm
+    return if confirmed?
+
+    super
+    update_statistics!
+  end
+
   def confirm!
+    return if confirmed?
+
     skip_confirmation!
     save!
+    update_statistics!
   end
 
   def promote!
@@ -202,4 +212,9 @@ class User < ApplicationRecord
   def sanitize_languages
     filtered_languages.reject!(&:blank?)
   end
+
+  def update_statistics!
+    BootstrapTimelineWorker.perform_async(account_id)
+    ActivityTracker.increment('activity:accounts:local')
+  end
 end