The $1-billion Grand mixed-use complex designed by architect Frank Gehry is about to open across the street from Gehry's Walt Disney Concert Hall. The project took nearly a decade to build and is still not fully complete — its shops and restaurants won't be occupied for another year. But its 436 apartments and luxury hotel are days away from opening, a landmark event in the redevelopment of Bunker Hill that has been going on since the 1950s.