If a Texas developer has his way, American high schools would take on a night job of sorts as after-hours movie theaters--and money makers. Schlosser Development Corp. wants to launch a nationwide chain of outdoor digital movie theaters on high school campuses--beginning with Mira Mesa High School in San Diego. This giant-screen theater, a modern take on a drive-in without cars, would offer free educational films to students during specified hours. Meanwhile, the public could pay to watch educational and family-oriented shows on an IMAX-like screen, with the San Diego Unified School District sharing as much as 50 percent of profits.