ATLANTA — For the first time in nearly a quarter-century, the Atlanta Braves are searching for a general manager. Frank Wren was fired Monday with a week to go in the regular season, taking the fall for a late-season collapse that knocked the Braves out of playoff contention. This will be only the sixth time in the last 23 completed seasons that the Braves missed the postseason, with a team that will be remembered mostly for its feeble offense.