LOS ANGELES (Reuters) - In the gritty, billboard-festooned Los Angeles neighborhood of Koreatown, at the heart of America’s largest ethnic Korean community, residents expressed bemusement and hope at the latest promise of rapprochement between North and South Korea. The first summit in a decade between leaders of the divided peninsula ended on Friday with a pledge by the two sides to work toward “complete denuclearization” and talks with the United States and China on an agreement officially declaring an end to Korean War of the 1950s.