It is closing in on 25 years since Peter McKenna first stepped through the gates of Croke Park — not as a spectator, but as the man tasked with reshaping its future.  The stadium was still a work in progress — part construction site, part cultural monument — and the financial strain was undeniable. McKenna, fresh from a corporate career at Smurfit, was about to trade balance sheets for stands and boardrooms for dressing rooms. Peter McKenna’s journey to becoming stadium director at Croke Park was anything but linear.  In 2001, McKenna was on the corporate fast track at Smurfit…