NEW YORK — Mitchell Robinson finally gets his big paycheck. The 24-year-old center, the product of rare smart Knicks drafting and patience, agreed to re-sign with the Knicks after a brief flirtation with unrestricted free agency, a source confirmed Friday. Robinson’s agents told ESPN that the deal is worth $60 million over four years, although it’s unclear if that includes any incentives or options. His agent, Thad Foucher, did not respond to requests for comment. The re-signing is both important and risky for the Knicks. At a tad over 7-feet tall with bounce, Robinson theoretically provides t…