Implement Instance Moderation Notes (#31529)

app/models/instance_moderation_note.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+# == Schema Information
+#
+# Table name: instance_moderation_notes
+#
+#  id         :bigint(8)        not null, primary key
+#  content    :text
+#  domain     :string           not null
+#  created_at :datetime         not null
+#  updated_at :datetime         not null
+#  account_id :bigint(8)        not null
+#
+class InstanceModerationNote < ApplicationRecord
+  include DomainNormalizable
+  include DomainMaterializable
+
+  CONTENT_SIZE_LIMIT = 2_000
+
+  belongs_to :account
+  belongs_to :instance, inverse_of: :moderation_notes, foreign_key: :domain, primary_key: :domain, optional: true
+
+  scope :chronological, -> { reorder(id: :asc) }
+
+  validates :content, presence: true, length: { maximum: CONTENT_SIZE_LIMIT }
+  validates :domain, presence: true, domain: true
+end