Decision
Supplies decision services by model name for models that are not registered as beans, such as the chat models a prompted decision service wraps.
The DecisionServiceRegistry asks providers only for names no registered service holds. It asks them in order and keeps the first service returned, so each name is built at most once. Defaults and roles may name any model in modelNames. A provider model never becomes a family default unless configuration names it.
Implementations must be thread-safe.