I've used these for years (found here)
git ribbonto mark latest main you've reviewed (like a ribbon in a journal)git catchupto review diff since then. (then dogit ribbonagain after reviewing, so it's ready for tomorrow.)
In your ~/.gitconfig, [aliases] section:
ribbon = tag --force _ribbon origin/main
catchup = log --patch --reverse --topo-order _ribbon..origin/main
This works best with delta, a really good diff viewer with syntax highlighting:
https://github.com/dandavison/delta
(You just do brew install git-delta (or equivalent for another package manager, it's widely available), then a couple changes to ~/.gitconfig as shown in its README, to configure it as the default diff viewer.)