Retrieves Orchestrator registration settings (connectivity IP/domain) for appliances.

Without nePk parameter:
Returns full configuration with customDefaultIP, internalManagementIP, and label mappings. The defaultIPOrDns field is excluded (set to null) in this endpoint.

With nePk parameter:
Returns resolved IP/domain for the specified appliance using this priority:

1. If appliance has WAN interface labels matching configured labels, returns the highest-priority matching label's IP/domain
2. Otherwise returns customDefaultIP if set, or first internalManagementIP
3. For appliances < 8.1.2, always returns an IP address (domains resolved to eth0 IP)

Container Mode:
When Orchestrator runs in container mode, internalManagementIP is empty since the container's internal IP cannot be used for appliance connectivity.