WASHINGTON — Secret Service agents apprehended a man attempting to enter the White House grounds Thursday morning — but not before a brief scuffle that left one officer injured.  “Shortly after 11:30 a.m., a man was quickly detained by uniformed US Secret Service police officers after jumping over a construction bollard near the Treasury Building on the northeast side of the complex,” protective agency spokesman Anthony Guglielmi said in a statement.  “Officers encountered the individual near a