Saved versions
Your app is a folder kept in git, which remembers every saved version of every file. You never use git yourself; you ask Claude.
Save a version
When a report looks right, ask:
"Save this version: the Orders report with the category table."
Claude saves every changed file with that note. Save often: after each change you are happy with.
See what changed
"What changed since yesterday?"
"Show me the difference in the Orders report since the last save."
Go back
"Put the Orders report back as it was this morning."
"Undo the last change."
Claude brings back the earlier version of the files and saves that as a new version, so nothing is lost.
Try something risky
"Try a version of the Orders report with weekly tiles, separately, so I can compare before we keep it."
Claude works on a separate line of versions and brings it in only when you say so.