SINKING SLOWLY INTO THE WEST-Carolyn Laubender, 17, of Thousand Oaks and Kelsey Laity-D'Agostino, 17, of Santa Rosa, are watching summer vacation fade into the sunset at Wildwood Park in Thousand Oaks. As high school seniors, they'll be back on campus soon. Next summer they'll embark on college and careers. Laubender said, "I wish I could freeze time."