A factory that constructs a registry entry from the service registry.

This is the "factory arm" of a registration option: an entry that is a function is called — once, at the onInit phase — with the application's IServiceRegistry, and its return value is the instance the option would have accepted. It exists so a generated artifact (a command handler, event handler, or health indicator) can reach a capability — the event bus, the logger, the database — that its contract's single message parameter cannot carry.

The argument is named services at every call site. It is deliberately the registry and nothing narrower: everything a generated artifact could want is reachable through it under a CAPABILITIES token, and a narrower context would ship with no in-repo reader.

Do not confuse with ServiceFactory: that is a no-argument lazy factory the registry invokes on first lookup, whereas this takes the registry as its one argument and is invoked by a plugin's onInit hook.