add hmac webhook secret

db/migrate/20260506120000_add_hmac_to_webhook_urls.rb

@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+class AddHmacToWebhookUrls < ActiveRecord::Migration[8.1]
+  class MigrationWebhookUrl < ApplicationRecord
+    self.table_name = 'webhook_urls'
+
+    encrypts :hmac_secret
+  end
+
+  def up
+    add_column :webhook_urls, :hmac_secret, :text
+
+    MigrationWebhookUrl.find_each do |webhook_url|
+      webhook_url.update_columns(hmac_secret: WebhookUrls::Signatures.generate_secret)
+    end
+
+    change_column_null :webhook_urls, :hmac_secret, false
+  end
+
+  def down
+    remove_column :webhook_urls, :hmac_secret
+  end
+end