Implement Instance Moderation Notes (#31529)

app/policies/instance_moderation_note_policy.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+class InstanceModerationNotePolicy < ApplicationPolicy
+  def create?
+    role.can?(:manage_federation)
+  end
+
+  def destroy?
+    owner? || (role.can?(:manage_federation) && role.overrides?(record.account.user_role))
+  end
+
+  private
+
+  def owner?
+    record.account_id == current_account&.id
+  end
+end