アイヌ語追加 (#428) (#433)

Reviewed-on: #433
Co-authored-by: miteruzo <miteruzo@naver.com>

backend/app/models/script.rb

@@ -1,5 +1,11 @@
 class Script < ApplicationRecord
   has_many :locales, foreign_key: :script_code, primary_key: :code
 
-  enum :code, Jpan: 'Jpan'
+  # Canonical keys come first so reads and plucks retain ISO 15924 spelling.
+  # Legacy keys preserve the existing enum predicates, scopes and queries.
+  enum :code, { 'Jpan' => 'Jpan', 'Kana' => 'Kana', jpan: 'Jpan', kana: 'Kana' }
+
+  def code= value
+    super(self.class.codes.fetch(value.to_s, value))
+  end
 end