Update procedure for already Specify Init-ed repositories

I would like to see a new command/option for the specify command that updates a repository that already has a .specify folder in it and that can update the content in the proper way.

At the moment the best option I've found is to init a blank project and copy the scripts and then do a manual merge of template and memory folders to understand if they were upgraded in significant way or not.

- Is this the best way?
- Is quite ripetitive and error prone, a "specificy upgrade /here" would be preferred (maybe as a starting point for a /speckit.upgrade command to be given later that update templates using AI assistance)