I have no experience with a ruptured Achilles, but if I had, my greatest concerns when squatting would be if I got a little off balance that catching my balance could involve the Achilles’ tendon.
If you could avoid walking out of the rack would be nice. A monolift would be nice.
I would think easily managed weight would be safe deadlifting.
Of course when doing either with warmup weight and there is pain, STOP. Don’t do it.
While recovering from surgery I would just to a push/pull 4 day split. You just must pick exercises that don’t put weight on the recovering leg. I have worked around numerous injuries throughout my lifting life.