MinecraftUiPlatform
Owner-thread platform services used by Minecraft-backed components without exposing version-specific game types.
One host owns the platform from successful construction through terminal close. The host may memoize an admitted successful image result for each identifier; a new platform and host are required to expose resource-pack replacements reliably. The platform may lend stable bindings to retained nodes, but close releases every observer, item snapshot, callback, and native reference.