TREKKIE: Mr. Spock wasn’t the only familiar face to turn up last week on “Star Trek--The Next Generation.” Orange County theatergoers also may have recognized a Star Fleet admiral, played by Karen Hensel, who is a regular on stages at South Coast Repertory in Costa Mesa and the Grove Shakespeare Festival in Garden Grove. . . . “It’s one TV show where Shakespearean training is actually an asset,” she says. The two-parter concludes tonight at 9 on KCOP Channel 13.