Cosmetic Thrall NPC

Bug fixes:
- Fixed an issue where the Thrall's mesh position resets to 0,0,0 when reloading a session while mounted on a dino, causing the Thrall to float in mid-air. The position is now periodically corrected while mounted. Most noticeable on dedicated servers.
- Removed the vanilla behavior where the Thrall randomly mounts a nearby dino when entering combat. This was causing critical issues — most notably interrupting dino mating by jumping on one of the pair mid-process.
- Fixed a bug where the follow target was reset after rejoining a session. The Thrall will now correctly remember its follow target after reconnecting, including when the follow target is another Thrall.
- Fixed an issue where multiple Thralls teleporting simultaneously would stack on the same spot and get stuck together. A random spread is now applied to the teleport destination.
- Fixed an issue where the Thrall was spawning slightly to the front-left of the player. The Thrall now spawns directly in front of the player.

Adjustments:
- Increased the auto-teleport follow distance threshold from 5000 to 7000. This reduces the frequency of teleportation when following the player.