Design a Registry with REGISTER and SET_HEALTHY Operations (Multi-part OA)

You are given a sequence of commands that arrive in order. Implement a “registry/service registry” that manages entities (e.g., instances/services). The core operations include: REGISTER ...: Register an entity in the registry and store its metadata. SET_HEALTHY ...: Mark a registered entity as healthy. The OA is multi-part (about 3 parts) where later parts build on earlier ones. For the given command input, produce outputs at required points according to the specification. Note: The post only mentions keywords (REGISTER, SET HEALTHY, three parts, very long prompt) but does not provide the exact input/output format, field definitions, required outputs, or edge-case rules. Therefore the problem cannot be fully reconstructed without guessing.