Niners nearly violate PUP rules with Crabtree

49ers receiver Michael Crabtree remains on the Physically Unable to Perform list.  If he’s not activated by Saturday, he’ll remain there for at least six weeks. And since he hasn’t been activated yet, he can’t practice with the team.  On Monday, he almost did. Matt Maiocco of CSNBayArea.com reports that Crabtree, who was not in…