Database.add_cluster(level, name, members)

Add or replace one stored shock cluster.

members accepts a regional mapping when the set is regional, for example db.add_cluster("Activity", "selected", {"IT": ["A2"]}). List shorthand is also accepted and intersected with each region’s domain. Existing clusters are retained; the named cluster is replaced as a complete definition. See mario.Database.set_clusters for validation and omitted-region semantics.