STOCKTON — Imagine if you will a service designed to meet all the medical and social needs of the community’s frail seniors with the goal of keeping them out of nursing homes and hospitals.And for most participants with Medi-Cal or a combination of Medicare and Medi-Cal with no share of cost, all of its services are free.If you’re from any other California metro area, you may be familiar with PACE, or Program of All-Inclusive Care for the Elderly.