バグ対応（#253） (#255)

#253

Co-authored-by: miteruzo <miteruzo@naver.com>
Reviewed-on: #255

backend/db/migrate/20260126124100_add_unique_index_to_ip_addresses.rb

@@ -1,3 +1,5 @@
 class AddUniqueIndexToIpAddresses < ActiveRecord::Migration[8.0]
+  def change
     add_index :ip_addresses, :ip_address, unique: true, name: 'index_ip_addresses_on_ip_address'
   end
+end