Fangs 'n Claws

Fix missing entity_type tags (silver skeleton now undead/skeleton so Smite works and it no longer swims, scorpions now arthropod for Bane of Arthropods, ice golem/frost scorpion freeze-immune, fire mobs freeze-vulnerable, mod arrows and rideable mobs tagged), add missing Sturdy Saddle recipe, fix leash not working on tamed mod horses (canBeLeashed was always false because HorseMob implements Enemy, and mobInteract consumed the lead), fix tamed scorpions using legacy OwnerUUID instead of vanilla Owner (broke friendly fire, Jade and mod compat), fix Sturdy Saddle not dropping from a saddled scorpion, harden mushroom fields/deep dark spawn exclusion with a datapack-overridable biome tag