Merge pull request #68 from amatsuda/add_index_again

Add index to messages on message_id_header (take 2)

Author: amatsuda

db/migrate/20251017161507_add_index_messages_message_id_header.rb

@@ -0,0 +1,5 @@
+class AddIndexToMessages < ActiveRecord::Migration[8.0]
+  def change
+    add_index :messages, :message_id_header
+  end
+end