The client's change report is the file journal

Month-end. The retainer client asks what you changed. Their CFO needs it for the invoice; their head of product needs it because something moved.

Every file mutation in their container is already journaled by hoody-files. You send them the ?history URL on their site folder. Every edit, with a timestamp and a content-addressable revision. They pick two points and ?diff between them. They ?at= the first of the month and read the site as it was before you started.

Nobody on your team reconstructed the month from Slack. Nobody wrote a changelog from commit messages that say "fix." The report is the substrate's own record, and the client can ask it harder questions than they'd ask you.