Ninja: mounted chain-dagger prototype

What’s changed

• Added a mounted attack prototype with two daggers linked to the hands by chains, spinning beside the horse.
• The blades retain the model and textures of the equipped daggers.
• Reworked arm and wrist movement and updated collisions to follow the spinning blades.

Run CHECK UPDATE in the launcher before entering the game.

These notes describe the game at the time of each release. Check the in-game Wiki for the current rules.