The rollback idea is solid.
Feels like that’s one of the missing pieces right now, because most agent systems assume forward progress, not safe recovery.
Only thing I’ve noticed is rollback works great for state, but gets tricky once actions have external side effects, APIs, data writes, notifications, etc. At that point you can revert the system, but not always the impact.
Still, having a clean way to step back is a big shift compared to most setups today.