New fields in SiteHealthReport: NodeHostname, DataConnectionEndpoints
(primary/secondary), DataConnectionTagQuality (good/bad/uncertain),
ParkedMessageCount. New collector methods to populate them.
Health dashboard redesigned to match mockup: Nodes | Data Connections
(with per-connection tag quality) | Instances + S&F Buffers | Error
Counts + Parked Messages. Site names resolved from repository.