hpfxd/SpectatorPlus ? reverse-engineered prompt

Build me a Minecraft spectator mode mod that makes watching another player actually useful. When I spectate someone, I want to see their held item and health, and if the server side mod is installed, also show their hotbar, food, experience, and whatever screen they currently have open like a chest or crafting table.

It should also fix the annoying spectator bug where you get kicked out or lose the target when the player teleports far away or changes worlds, and that part should still work even for clients that do not have the mod installed. Please make it work for Fabric, and if the server side supports Paper too, keep that support in mind for the screen syncing feature.

If permissions are needed, set it up so server owners can control who gets each bit of extra spectator info, but default to everything enabled so it works right away.