The Walnut Creek campus of John Muir Medical Center is growing by leaps and bounds. That’s good news for local residents, who depend on the hospital as the only certified trauma center for Contra Costa County and part of Solano County.   A recent $621 million expansion included a new five-story, 347,000-square-foot patient tower and 92 new beds, a roof heliport, and a lobby featuring a sky-lit rotunda. The medical center’s new emergency department added 25 beds as well, which...