The state’s new ResilientCoasts Initiative lays out adaptation plans to protect people, infrastructure and ecosystems—a costly effort that officials say will save more than it spends.By Ryan KrugmanA long-awaited advisory plan to protect Massachusetts’ 1,519 miles of coastline from intensifying storms and sea level rise—an effort years in the making as tides creep higher into coastal neighborhoods from Salisbury to Cape Cod—has been released by state agencies.