HOUSTON — Texas Attorney General Ken Paxton on Tuesday agreed to pay nearly $300,000 in restitution under a deal that ends criminal securities fraud charges that have shadowed the Republican since he took office nearly a decade ago.The announcement by special prosecutors in a Houston courtroom came less than three weeks before Paxton was set to stand trial on felony charges that carried a possible prison sentence if convicted. It was the closest Paxton — who was indicted in 2015 — has ever come to trial …